Oh, you'd think so, wouldn't you?
Couple of years back I tried to build my dad a cheap wordprocessing machine. I got a pentium II, 64MB RAM-type one, put Ubuntu with fluxbox and Abiword on it. Boot time: 4 minutes. Time to usable Abiword: 2 minutes. Probably spent most of that swapping in and out. Then the UI was _crawling_. My dad quipped that "wow, Linux must be for rich people".
So I had to swap that with a Win98, Word97 setup and suddenly it was flying.
When this sort of box was the state of art, Ubuntu didn't exist, and AbiWord was just starting out. Can't blame them they didn't care to make their product fast enough - after all, devs just use nice new machines, right?
On an old box Linux might be great for VIM but that's not all everyone needs :)