Indeed HTML is great for that, but the problem is that you never "level up". Once your content renders, you are done. A lot of Joes may be interested in how things work behind the scenes or in making things "correct" more than "just working". It would be great, from a pedagogical point of view, to have browser render Joe's content (for instant gratification) but also to point out that "Ehi, on line 32 you closed </p> before </i>. It should be the other way around because of this rule called nesting, have a look at it". I think we are wasting a lot of man-years around the globe for the lack of such warnings.
In the education of many people, compiler errors and warning had exactly this function: they made you do whatever you wanted (as long as decent) but they would also pointed out the basic mistakes ("Ehi, on line 14 you print the variable prg_name, but that variable has not been initialized, beware").
- Market floods with professionals who antagonize proper web developers, since, to unknoweledgeable clients, the result appears to be the same
- Web floods with sites that behave in unpredictable ways in different browsers
- Proper developers carry the burden of dealing with idiosyncrasies of various browsers
- Browser developers carry the burden of trying guess through amazingly creative atrocities
Although, to be honest, things don't look as grim as they used to regarding the middle two. I just wish some people would stick to HTML and stopped brute-forcing javascript to work.
(If you weren't online/sentient back then, sites commonly had these 'Best viewed in Netscape' badges on them.)
An average Joe is supposed to feel great about writing something that renders the way he/she wants without having to go into deeper stuff like semantics, validity or even cross-browser.
This is something that should be left to people who need to know it in their strata, isn't it?