I don't nessecarily hold published settings to higher standards than homebrews. After all, it was a published setting's forbiddance/acceptance that started this whole thing.

I'm not speaking for others, though.
It is true, though, that a published setting has more chances to earn the trust of the player. It's got feats, PrC's, history, setting info, and an entire company's funds riding on it. It's got a *shiny* hard cover. While that doesn't mean that it's nessecarily any good, it does mean that before you ever invest in it, the DM (the writer) has to answer to your demanding nature as a consumer. It's more than a post at the FLGS that says 'players wanted.' It's something presumably someone somewhere with access to capital and a publisher, thought a good amount of people would shell out $40 for. It has about 300 pages to justify itself, and only has to do it maybe 60-70% of the time (how many people buy campaign settings with the simple intent of homebrew cannibalization?). Part of the reason that a CS has it easier is because it has a lot of chances to show me that it's writer(s) are people whose rules I can happily play under.
One DM, however, pretty much has that first impression. And, I feel, my trust as a player has to be earned. I feel that the DM has to make me want to play in their game. It's not a matter of them accepting me -- it's a matter of me accepting their judgement. And I, personally, will only give someone the benefit of the doubt if they prove to me that I should. If I know nothing about them coming in, one of the best ways that they can do that is by being free with information, and telling me why they made the changes to D&D that they did.
I guess I might view it backwards from some. Whereas Bendris has an interview process for players, I'd rather have an interview process for DM's. It's my view that a single bad player ruins the game most strongly for himself, a single bad DM ruins the game most strongly for 3-5 other people he's playing with. It's much more important for me to have a good DM than to have a good player.