Algol 68 and Pascal weren't memory-safe, and as for Lisp, Smalltalk, and ML, their style of memory safety - based on GC - took over the world pretty much the second it became practical enough for widespread use.
It is true that some decisions people make aren't rational, and it may even be true that most decisions most people make aren't entirely rational, but the claim that the whole software market, which is under selective pressures, manages to make irrationally wrong decisions in a consistently biased way is quite extraordinary and highly unlikely. What is more likely is that the decisions are largely rational, just don't correspond to your preferences. It's like the VHS vs. Betamax story. Fans of the latter thought that the preference for the former was irrational because of the inferior picture quality, but VHS was superior in another respect - recording time - that mattered more to more people.
I was programming military applications in Ada in the nineties (also not memory-safe, BTW) and I can tell you we had very good reasons to switch to C++ at the time, even from a software correctness perspective (I'm not saying C++ still retains those particular advantages today).
If you think so many people who compete with each other make a decision you think is obviously irrational, it's likely that you're missing some information.