It is a fool's errand to try to evaluate the net societal impact of a particular technology, even with perfect predictive power.

Looking back, what technology would you have retroactively stopped? Tetraethyl lead? Perhaps. Nuclear? Cable TV? ANNs? The Internet? Drones?

Also, the financial incentives aren't aligned. Certainly it makes sense to hold back technology to avoid embarrassment if you're a trillion dollar company; you have more to lose than gain. However, if you're a scrappy startup, it makes way more sense to roll the dice.