No doubt, there's always some bad with the good. The counter is to ask about the proportions.

It's actually a sliding scale of badness, but for the sake of argument let's pop a marker on that imaginary badness line and call everything worse than our marker "bad" and everything better than it "good". Let's also assume such objective criteria exist. This is a lot of assumptions!

Now, assuming we got this far, is the "bad" 1% of the sum? Or 90%? 99%? Because we just don't know, I'm going to make another assumption and assume it's a tiny minority.

We still sell knives even though they can stab. Mostly though, knives do other knife things. And we have police and courts to deal with the bad uses.