As far as I can tell, it's much easier for people to add rules than to repeal them-- I call this rule rachetting.

Perhaps it's that once a rule exists, people have put work into getting used to it, and don't want to redo their habits.

However, considering that it's hard to get obsolete laws repealed, it's probably a status issue. Repealing a law means that the people in charge have to admit that the group they're affiliated with isn't eternally correct, and that there's some area of activity where the people who are lower status than the government are now going to be trusted to make their own choices.