Actually you're right, I think I got my wires crossed on that one, or just old misinformation from back then. 32 bit isn't exclusively single thread, but more games were built as single or limited amounts of threads back then. Might need to brush up on that.

EDIT: Yeah so Crysis apparently was entirely single thread for most/all functions, to this day people occasionally still have problems running it because of that, maxing out a single CPU core pretty hard. Might have to try it out at some point, see what it does to my rig.

Edit 2: So it's difficult to exactly say, but it looks like a lot of CPUs didn't support multithreading back in the day, and it was assumed that future CPUs would have higher clock speeds over multithreading capacity. I guess that was the motivation, that or they just need to wrap up development and the benefits of multithreading weren't as important at the time.