There was this question earlier today that asked "what is a good execution time for a web page in PHP". It was quickly closed as not a real question.
One of the answers was "Whatever is reasonable for the content that gets displayed..." and it was voted up to the top.
My opinion is that such an answer should be a comment, really, as it is not informative, and its sole value is the wit associated to it. A similar one-liner ("Uhm. Three and a half hours if it does something complex.") was even voted down.
However, it's obviously not the only opinion out there, as I got into an argument with two other users about whether it was acceptable or not.
So, meta, what do you think? Is it appropriate to answer vague questions with equally vague answers?