Anecdotally, there's definitely some truth to it being a matter of what you've grown used to. I moved from an old Windows desktop to a Mac OS X laptop. I found the fonts on Mac OS X to be exactly as you described -- fuzzy, bold, fairly annoying. After a month of heavy usage, I stopped noticing it. When I visited my old Windows computer a year later, I realized I perceived all the fonts as incredibly jaggy, thin, and hard to read. But after a while (1 week) I stopped noticing as much.