Well, first of all, if I were the sort of person who sells herself out and writes to trends I can't stand just so I can get a big fat paycheck, I wouldn't be stupid enough to admit it on a public blog.
But, seriously, do I write to trends? Not really. I have weird taste in books, and I think I might be the only reader in the world who finds "likeable" protagonists boring. Also, I'm not a huge fan of romance or really happy endings.
But would I make some revisions after an agent or editor asks for them? Yes, if those revisions would make my story stronger. This year, I read a highly-anticipated sequel to a book I enjoyed a few years back. This author is very popular in the fantasy genre, but his sequel didn't live up to my expectations. It was about 1000 pages long, and at least 150 pages of that book didn't need to be there--and if he weren't such a popular author, then I'm sure they wouldn't be. So yes, editors are your friend.
(That, and contrary to what Anne Rice thinks, even Hemingway had an editor.)