That doesn't really refute the point that Carmack made. Namely that a lot of the supposed inherent difficulty in the endeavour of debugging is actually incidental from a general cultural attachment to crap old tooling.

And I believe the point of Kernighan, as well as Torvalds, is that the difficulty of debugging serves as a bulwark against over-complicated code.

So that's why ed(1) is the standard text editor. Anything more usable is a dangerous extravagance! :)

Sounds like Brian has never used a good debugger

UNIX has never been the place of cool graphical debugging anyway.