For all my "old man shouts at clouds" posts about M+KB not working for this I totally get why they have done it. It just wouldnt work on a M+KB.
they could have made the menus work with a mouse though!
I find mouse/kb essential in first person games with aiming, while third person melee games are better with a controller. The menus should definitely support mouse though, it reminds me of old dos games with keyboard menus.