there's no accounting for taste

Some use this phrase to imply that another person's preferences are peculiar to them, perhaps low-class or stupid. I use it merely to get the point across that I don't have a taste for the item in question (say, asparagus on toast, which my next-door neighbor in Lambda Hall used to eat). No mockery of a person's intelligence or upbringing intended.

This expression probably originated when "accounting" would be understood in the Biblical sense -- that is, accounting for your life at the pearly gates. The common (but inaccurate) understanding is that in the Christian afterlife, your good and bad deeds are looked at and your admission into Heaven is granted or denied based on those deeds. Personal taste, however, is not a deciding factor.

The implication in context is that while the speaker may not approve of the subject's fashion sense, home decor, or CD collection, they understand that such things are a matter of preference and not a basis for judgement.