Why do people feel the need to mention they're using a Mac?

Direct reason for posting this question is an answer to another question regarding podcasting tools for Windows. While generally a good answer, the last line struck me: Personally I use a Mac which includes podcasting tools “out of the box.”
What I found most “disturbing” was that the questioner specifically asked for Windows tools. I can understand that, when asking for podcasting tools in general, you can recommend Mac ones, but really, what’s the added value in cases like this?