I think the difference between "don't implement workarounds" and "use overcommit" is that the kernel can try to be clever, but userland should not have to be clever. The kernel is supposed to just make things work for userland.

I think that's why overcommit exists. It's generally not easy to re-design all userland applications to deal with difficult memory management problems in a complex system, but it is easy to just lie to them all so they can continue to do stupid things and not crash. If you have a system with only "100% correctly written" software, just disable overcommit (echo 2 > /proc/sys/vm/overcommit_memory).