C was already implemented on several quite different machines and OSs, Unix was already being distributed on the PDP-11, but the portability of the whole system was new

It's true that compared with the scene when Unix started, today the ecological niches are fairly full, and fresh new OS ideas are harder to come by, or at least to propagate.

Obviously, the person who had most influence on my career was Ken Thompson. Unix was basically his, likewise C's predecessor, likewise much of the basis of Plan 9 (though Rob Pike was the real force in getting it together). And in the meantime Ken created the first computer chess master and pretty much rewrote the book on chess endgames. He is quite a phenomenon.

Steve Jobs has said that Xwindows is brain-damamged and will disappear in two years. He got it half-right.

A language that doesn't have everything is actually easier to program in than some that do

I'm still uncertain about the language declaration syntax.

C is declining somewhat in usage compared to C++, and maybe Java, but perhaps even more compared to higher-level scripting languages. It's still fairly strong for the basic system-type things.