It would be pretty difficult to ban water sports activities and prescription meds, which both have a positive purpose for society.

Handguns? Positive purpose? I don't think so.

All the US has to do is make them restricted weapons that are difficult to procure without proper training and have a long cool down period before acquisition. In Canada one can legally own a handgun, but it involves having to join a gun club, pass practical and written tests, and go through a very complete background check.
And it cannot be carried on the person without a temporary permit to transport. So it must be locked up in your home, or locked up at the gun club.

You want personal protection on the go? Then just trot down to any sporting goods store and buy some bear spray. At least it won't kill anyone accidentally.