Yes the pilots should have set the flaps for take off but they didn't because the mechanics disabled the take off warning system when they pulled the circuit breaker for the TAT. They forgot and had no back up. Both screwed up. We have learned from this.
The disabling of the TO config. warning has nothing to do with them forgetting. They forgot because they rushed and got complacent. It is just unfortunate that they did so on this occasion because they had no redundancy to catch
their mistake.
Nothing makes me go slower than someone who is rushing or says "we need to get going".
Planes can't be built to prevent all human mistakes. There will always be a weakness in every system. But we can prevent commercial factors from putting pressure on the humans which we rely on to avoid those system weaknesses.