Am I the only one who learned how to play beat-em-ups with the ASW games? My opinion is solid as a house of cards, I'll admit, but I thought P4AU wasn't a bad choice.
There's several mechanics in the Arena games that just... don't make for a good upbringing when it comes to fighting games. The issue with learning fighting games is that every single game will teach you bad habits. SF4 will have you crouch teching, Marvel will have you chicken blocking, Skullgirls will have you doing Push Block Guard Cancel reversals, and Melty will have you mashing 2A before you know it.
The Arena games have a four button layout, that's correct, but the issue is that it's not a 3 strength + one utility setup. It's literally Light, Persona Light, Heavy, and Persona Heavy. The buttons don't match up with other games in that sense, and because of the way the default layout functions, some people won't fully understand the difference between it and an ABC+D fighter. Another big issue is having your invincible reversal on a button press (it's on B+D, is it not?) since that allows a lot of people to turn their brains off when it comes to reacting properly to mixups and doing an input on the proper side. It will likely cause issues for anyone who relies on this far too much when they go into other games because they won't have that option anymore.