If something is mandatory on Wikipedia, that means that if you want people to follow it you need to _convince_ them that a) it is mandatory, b) they should follow things that are mandatory.
Just like absolutely everything else on Wikipedia.
How can you "enforce" anything like that except by jawboning?
A "mandate," the dictionary says, is "An authoritative command or instruction." But what, exactly, does "authoritative" mean on Wikipedia?
Who's going to enforce these "mandates?" Is Jimbo Wales is personally going to micromanage discussions on talk pages? Are we going to restrict the "move" button to Bureaucrats?
To riff on Mark Twain (or perhaps it was Oscar Wilde, or Dorothy Parker):
How many mandatory policies do we have if we call the Manual of Style mandatory?
Answer: We have none, because calling a policy mandatory doesn't make it one.