I defected in 2002. Quite a few reasons:
1) Needed to work on large graphics files, Photoshop 2 + Shapeshifter wasn't enough.
2) Office
3) Hardware based encryption
4) Raytracing and Poser
Probaby the biggest issue was RAM and processing power. When you are working on a 600mb TIFF, the 060 A4000T and its 146mb RAM doesn't cut it.
Even today, with my PPC and 530mb RAM, it wouldn't be enough. At the time I defected, games and internet weren't an issue for me. I was happy using my PS2 and I didn't mind using the internet cafe.