It's just the usual HN selection bias--Mac apps appear disproportionately frequently. A cool Windows or Linux only app wouldn't get the time of day from the large Mac-using HN contingent.

Also, for whatever reason, the majority of open source Linux programs are actually cross-platform, whereas Mac developers seem to have no compunctions about only supporting a single platform.

The answers could also be correlated. If you asked why there is a selection bias among HNers with Mac usage

...because thats where all the cool apps are.

Because all designers use macs.

We already have FeedDaemon on Windows...

Which just underlines his point. Feed Demon is functional all right, but I would not call it cool. In fact, I usually prefer to use my smartphone instead of Feed Demon.