I thought you said that the hidden-variables extension of quantum mechanics is "bad" (compared to the "vanilla" QM) because you need to allow information to travel faster than light speed.

But I agree if you meant that QM (both non-local hidden-variables and standard interpretation) requires non-locality, unlike local hidden-variables theories which are ruled out by the violation of Bell inequalities which has been established experimentally.

Hidden variables where specificly proposed as a solution to non-locality. So, I just mean bad in that they did not solve that problem.

True. However, unlike the "standard" QM interpretation, the non-local hidden-variables theories are deterministic (which is the reason why they were mentioned in this thread a few messages back).