We still have maybe 40 or 50 single core systems in my college. Sure, they aren't as quick as the newer dual core systems we have, which also have never architecture, more memory, newer chipsets, faster HDDs etc, but they still boot up and read emails, type up work, do some research, check bulletins etc withing a minute or two (not the typing up and research, I slow that down alot

). Single cores aren't bad at all, they are just getting outdated but still more than sufficient for certain applications.
As for you disliking casual users, take them out and see how fast the computer market would fall and see how long it would take to develop new software and hardware for enthusiasts when they have to make the majority of their R&D and manufacturing workforce redundant thanks to them losing massive amounts of profit because that sector isn't there. Not everyone knows everything about computers, not everyone knows what a component does, what it looks like, what the numbers mean, they just want a system that will meet their needs and is within their budget. There isn't just the best of the best and gaming in this world, there are, it may be hard to believe, people that just surf the net, upload and look at photos and videos, listen to music, do online banking, send emails and type up the odd document. The cheap stuff is more than enough for them
spot on, there are going to be *SOME* faster pentium dual cores, but in general the C2Ds are faster