>>>Isn't it possible that thin and low-quality pages can rank near the top simply because there isn't anything better?
That isn't what's happening. Here's a very specific example I saw.
I wrote a very detailed, long, authoratative article on a very specific subject a few days ago. More than 1000 words. There are 4 or 5 other long, detailed articles on the subject online as well. If I now search for the keyword which that article very specifically pertains to, of the 10 results on the front page 6 of them are basically blank pages with ads on them and a bunch of keyword stuffing to make them appear high in the SERPs.
One of them is someone who has scraped my article.
The other 3 don't relate to the keyword at all, but belong to big brands.
My article and the other 4 which are thick content and actually pertain to the keyword, don't begin to appear until page 2.
On Bing, the same search returns all 5 articles on the first page.