The reason for that is because you can fuck off with the persistent harassment of those who come to get abortions, including by "praying", that is, hanging around near the clinic trying to guilt-trip pregnant women. You're completely free to fuck the fuck off away from the area and bow your head disapprovingly. You're also free to think whatever you like inside the designated safe zone so long as you're not being demonstrative about it. Anyone who's deliberately come near to the clinic in order to visibly pray is picketing it. Having a grievance about this as if it was thought policing is dishonest.
If it were a fish and chips stand there'd be no problem with picketing, praying, or most other nonviolent, non-threatening demonstrations that didn't get in somebody's way. You could make it your full-time job to protest every fish and chip stand in the country without issue. It _is_ thought policing, since the only crime is protesting the "wrong" thing.
Maybe it's still fine to ban that sort of protest, but let's call it what it is.
Harassment, yes. To get an equivalent situation, you need to eat a fish supper to avoid monumentally unpleasant life changes, and the looney fringe of the dominant religion, in cahoots with some of your friends and relatives, wants to call you a murderer for eating that fish supper. Then they don't limit themselves to publishing their views, they hang around the fish and chips stand acting sad and concerned. This is not a constructive discussion or public debate, it's coercion.
