I mean, I get the whole "don't depend on another company for your revenue" (e.g. apps in the Apple app store), but you're saying "don't count on Google sending traffic to your site".
Plus, her ranking didn't change -- her site vanished out of the index.
EDIT: Unless you mean "don't depend entirely on organic traffic"? I can sorta see that... but, again, if I've only now thought about putting a photo on a quilt (which is a new idea to me), around 70% of the US thinks putting [photo quilts] into Google is the way to get the site you want. What else would you suggest?
EDIT #2: Maybe "vanished" is too strong a word, since it does show up on string matches. But it was deindexed for search terms it used to rank for.
The article is just idiotic in its accusations. Google wants to provide the best search experience for customers. If it makes a mistake, it hurts Google, so I'd imagine they sorta try to keep their results as good as possible. Complaining that you moved in indexes seems sorta pointless. Google's algorithms, at the moment, think other sites are a better match. Maybe she unknowingly engaged in some blacklistable offense.
It's like complaining that some hotel concierge stopped referring people to your restaurant.
It's safe to say, at this point, that we don't know why her site isn't showing up for the common terms it showed up for before.
EDIT: This comment has some good info on why her site might've been penalized: https://news.ycombinator.com/item?id=6891141
"...but if you look for photo quilts or any similar search term, Portrait Quilts — which for years was always the top result — no longer appears."
I'm being a little imprecise, but her site was deindexed for a bunch of search terms that she used to rank highly for.
Additionally, far less than <1% of the people who use Google get past the second page of results. Getting your ranking penalized by twenty spots is a death sentence.
Edit: Even for "portrait quilts" in quotes, her site shows up on the 8th page for me (opened incognito window to limit customization).
Maybe it's a quibble, but most humans don't put quotes in their search terms.
I disagree with your moral though, a moral would suggest a choice, and it would be difficult to not depend on Google for exposure here since they are the dominant source of identification. It is perhaps a poor choice to depend on Google for 'organic' exposure however.
That's a function of inaction however.
Moral: don't base your income on something as volatile as your Google ranking