Thanks for the suggestions!
This game was created for a specific hardware in mind, and played on that hardware when it was released. It had an analog joystick and two buttons, so we mapped the game to be playable on that: joystick moves and jumps, one button attacks, one button defends AND dashes if defend while moving.
We didn't have 4 buttons to map all actions that way, and even though, for an arcade (an actual arcade machine), wouldn't 4 buttons be too much?
Then we release with minor adaptations to be playable with PS4/xBox controllers. I guess PS3 too, but we haven't tested.
We might consider this remapping on a future release, though. Thanks!