Don't like something? Don't comment. This is just balls-out rude. Yes, I know, the food may not be to your liking; you're an alkie and she's a teetotaler; or her "remove the shoes" rules don't mesh with yours. Unless s/he's causing you bodily harm, keep quiet.
Offensive guest-to-host behaviors I've seen:
- Drunken guest removing artwork off the host's walls and parading it around the home, providing verbal commentary as he walked.
- Blunt guest telling host, "Your salsa's too warm. Maybe consider the freshness factor in the future."
- Unshod guest complaining about shoe-removal rule all night long. Loudly.
If you have a special request for your host, let him or her know ahead of time, or take your host aside and mention said request.
But rude commentary on food, drink, artwork? Not cool.