The underlying motivation for "notable" is a potential bug in Wikipedia, not a problem with "notability" per se. The notability requirement is epiphenomenal, a kind of code smell for the Wikipedia guidelines.
The underlying issue is whether the Wikipedia attribution and citation guidelines are strong enough to indicate when an article contains content that is possibly fallacious. Non-notable topics are more likely to have fewer references, and hence the information about a non-notable subject are more subject to manipulation.
It would be an interesting acid test for Wikipedia (perhaps a sub-Wikipedia, like http://everything-en.wikipedia.org/) to open the floodgates on "non-notable" entries. Articles would start out by default with a banner that says "No editor has reviewed whether this article contains credible sources." Another editor could swoop in, read the citations, and remove the banner, or change it to: "The sources cited in this article are easily manipulated, and lack independent review."
Iterating over http://everything-en.wikipedia.org editor guidelines, Wikipedia could evolve a strong set of guidelines for remaining authoritative over the long-tail of information.
I wish this would happen, but I don't know if/how it would.
If you do have good sources for something, e.g. there is even a relatively small biographical section on someone in a published book, or a journal article, or something similar, the separate "notability" requirement has been increasingly going away, so that "but I've got sources" trumps it. I wrote a bit on that last year: http://www.kmjn.org/notes/wikipedia_notability_verifiability... (I also discuss some of the history around these requirements, some of which were motivated by trying to do something about Usenet physics cranks who found Wikipedia and decided it'd be a great place for articles on all their pet theories.)
I've been systematically going through several references and adding articles on everything in them, and haven't run into people objecting to my articles or trying to delete them for several years, since the end of the more "notability" focused era. Now as long as my articles include some references, they seem fine. One of my projects is marching through the Allgemeine Deutsche Biographie adding articles on random people who were mayors of Prussian towns in 1850, and that kind of thing. There's even a Wikiproject trying to organize efforts to cover everything in that particular reference: http://en.wikipedia.org/wiki/Wikipedia:WikiProject_Missing_e...
I do think it's also valuable for there to be other projects, which catalog information that can't be referenced well. For example, Know Your Meme does a pretty decent job of doing original research in history-of-memes. There are several genealogy projects that attempt to catalog people more exhaustively as well. But those are pretty different projects from Wikipedia's goal of summarizing stuff that's published in the existing literature, with references. Wikipedia doesn't have to be the only wiki on the internet, so I don't see why those original-research projects can't develop in parallel.
I do think there are specific areas that remain more controversial, mainly around recent pop culture and business. If people suspect you're self-promoting, then they may try to get an article deleted (there was a recent rash of hotels hiring PR firms to add articles on them, which wouldn't be so bad in itself if the articles didn't read like ad copy). Same if you write an article on a recent internet meme, or a website.
In the areas I've been working in, which are mainly geography, history, science, mathematics, and literature, "notability" as a separate requirement seems basically completely dead in practice. I used to have to argue against deletion of my articles on minor 19th-century Prussians. But nobody even thinks of deleting those these days, as long as they have solid citations.
edit: Looking elsewhere in the thread, it looks like your views of Wikipedia are generalized from one very self-interested example: an article about your dad. May I suggest that isn't the most unbiased way of forming an opinion on a complex subject?
With copyrighted encyclopedias, my preference is to use at least 2-3 sources for a bio. For example, with a physicist, I'd use a biographical dictionary / encyclopedia as a reference for basic biographical facts (dates, locations, awards, etc.), and then flesh out information about scientific importance from something like a textbook or survey paper commenting on his/her work.
If the main source is a non-encyclopedia, it's usually less of a problem, because the original text doesn't really read like an encyclopedia article anyway. For example, when writing articles on Greek archaeological sites, my source material is usually a discussion in a monograph or history book, which is sometimes scattered (it may be mentioned for a few pages in Chapter 2, then again in Ch. 8, sometimes as a main topic, other times in passing when discussing an event or person, that kind of thing). So it's a matter of going through, noting down salient facts and page numbers they came from, and then assembling the results into an article.
See Rob Pike's[1] Wiki page, for example; it's just a couple of paragraphs describing where he was born and what he did and does professionally. From his personal life, there's only 8 words.
I'm someone who likes to remain pseudo-anonymous, but I'd be OK with a page like that.
Then they get used to it.
While I think a lot of people would get used to it (as proven by the amount of people who have all their lives and conversations in public on Facebook), there definitely will still be some who are aware of the consequences. The whole "overshare your whole life publicly on the internet" situation is starting to get out of hand. I don't need to tell HN'ers, but once something is put online, it's there forever, available to any of the 7 billion people alive right now, and it will be available to anybody else that ever lives in the future. Yet still people continue to post content that is immature, embarrassing, risqué, illegal/incriminating, etc. using their full names and identities for the world to see. But a full Wikipedia article for every person? Do you really want anybody on the planet to have your full DOB, birthplace, educational history, employment history, place of residence, pictures, etc. AND then have all of that information for your spouses, parents, children? This is getting too crazy.
And if we did? It think it would be rather cool for everyone, living or dead, to have his own Wikipedia page. In fact these might have special status as non-deletable.
If your family ran a web site about its family, would you deny any member a page, especially if some members already had pages?
Now consider our larger family, all us humans that have ever been and ever will be. Besides the many topics about our "family" covered by Wikipedia, some of us have pages specifically about us. Why shouldn't all of us have our own pages?
Well before Wikipedia came along, I've wished that each person on Earth could have some way of being recorded for posterity. Some peoples' record will of course be more interesting than others'. But we're all family, even the boring and embarrassing ones.