Mathematics, as we all know, is a diverse forest full of interesting, strange, natural, obscure, appealing, highly abstract, and intuition-defeating topics: depending on which researcher you ask the labels vary from area to area.
It is my impression that the topics I find especially appealing (combinatorics finite and infinite, set theory, general topology) are "over-represented" on MathOverflow as I see a lot of activity in these areas, but comparatively little activity in what I perceive to be "hot topics" like algebraic geometry and analysis.
Question. Is my perception skewed? Or is MathOverflow (for some reason to be determined) more attractive to foundationalists as opposed to mathematician working in fashionable areas?