That won't stop the bad guys from making those tools while the good guys don't, because they are afraid their tools will be used by the bad guys.

Ignorance is not a good defense strategy.

Inadvertent bad guys (good intentions with unpredictable errors) can be more damaging than intentional attacks.

Can you cite an example?

Any well-known vulnerability, e.g. heartbleed, gotofail, etc.

I am genuinely interested in hearing the 'good intention' explanation of these bugs.