I don't accept this premise. Even if you ban swimming pools, that doesn't prevent children from drowning while swimming in the ocean, or lakes, or rivers, or even backyard swimming pools. All of those environments are just as much (or more) of a risk, and far more difficult to adequately cover even with the most well-trained lifeguards. Should we prevent children from learning to swim, or enjoying the water, even in a relatively controlled environment?
It's about limiting risk: kids can die both while driving a car and being a passenger of a car, but that doesn't mean it's inconsistent to ban child driving. For young children especially, drowning in pools is the leading cause of drowning, much more than natural settings, which are relatively rare (for young kids, bathtub drownings are next after pool drownings.)
I said most, because I see a place for swimming pools that are monitored closely by lifeguards and that offer swimming lessons. I'm thinking more of private, backyard swimming pools.
