It means it's only capable of processing the same number of threads as it has cores. A chip with hyperthreading can, for example, process four simultaneous threads, or processes, if it has two cores with hyperthreading whereas a chip with a dual core and no HT can only process two.
Except that that's two years old and there are a lot of game titles now, as you know, that ARE optimized for multiple threads. Aside from that and the fact that Linus is annoying, it's fairly on point.
I mostly just wanted to interject how I think Linus is annoying. Heh. I can't stand that guy, he's like almost as annoying to me as fingernails on a chalkboard. But he does present explanations in a way most novice users can understand.