Sure, I don't disagree. Personally, after moving away from BASIC to other languages, I felt freed from a bunch of problems I had had with BASIC. For example, scope eliminated problems with reuse of variable names. Perhaps lots of other people who started with BASIC felt the same way.

On the other hand, sometimes other people never transcended those bad habits from BASIC. Sometimes you run across programs that are one big function, with variables reused, etc. I don't know what the thought processes are of programmers who write such code. There's an old saw, "You can write FORTRAN in any language." Maybe this should be applied to BASIC as well. That's probably what Dijkstra was driving at. I don't know about "mental mutilation" (certainly hyperbole, in my book) but only Dijkstra knows what he really meant.