That's because there's a big amount of people, myself included, who feel like drug prohibition is good, all things considered. Not because "editing" the law is hard. (I am not American).

That doesn't make the situation different. All of these bad laws have supporters. (Largely because charlatans in government, law enforcement, and media constantly exaggerate dangers, but that's beside the point.)

By "bad law" I meant laws with absolutely no public support, not laws which are "objectively bad" (such thing made doesn't make sense)

There's plenty of public support for even the most dystopian laws.