Just that they think that using house rules everyone agrees on is a great idea.
I can think of one or two times where house rules were appropriate, and a couple of dozen times where they broke the game. I think that you should only apply a house rule where 1) the game is already broken and 2) you’re reasonably sure that the house rule won’t break it further. It’s good for when an otherwise fun game is ruined by something that the game designers overlooked.