If they can't control themselves we really don't want them wandering around the streets, we want to know where they are. Constant monitoring is an important reoffending protection measure for some sex offenders.
This comment about sex offender lists being full of people who had a single piss in public, but whenever I've asked for evidence people post maybe three or four examples.
Feel free to show me research that these public urinators aren't people flashing to children.