C was barely feasible on a PDP-11, so I can forgive it a lot, but we can afford powerful languages now that CPUs are thousands of times faster while brains are pretty much the same.
What do you mean barely feasible? C is basically a slightly abstracted/elevated syntax with a particular calling convention on assembly language, and PDP-11 is just a computer (that i remember too).
I’m under the impression that the speed and memory of their PDP-11 were barely enough to run their C compiler, considering that Emacs was considered a heavyweight app and S-Algol had to target a virtual machine instead of native code.