This isn't about protecting people from being idiots; it's about protecting people from idiots.

DUI bans aren't about the drunk drivers, they're about the innocent third parties they kill and maim. Ditto the requirement to hold third-party insurance when driving a vehicle.

I suspect that what's needed is not merely a ban, but a public education campaign to ram this point home. ("Do you want to be maimed by an idiot who can't pull over to answer a text? If not, don't do it to other people!")