Because MS and Sony wouldn't let them. Not with the console like it is.
With some games where the console is active on the consoles, most of the commands are locked out or restricted so you can't screw everything up.
With Beth's games, that would take more work so it's easier to just lock it off altogether.
And you could have just asked this in your other thread. The mods won't know any more than the rest of us, they aren't Beth employees.