Few members do, that's true, but for those who want to do minor edits, such as only making the thok item spawn and not propel you foward, or having JTE's wall kick from SPMoves and just "vamping" it, it could be useful. Also if some people want to have it that characters fly more forward than up, such as Rouge and Cream from Sonic Heroes. It's also useful if you want to set it that a character has psychokinetic abilities like Silver. What I mean is, say he uses light dash to use psychokinetic abilities like grabing enemies and solid objects, and you use the "ringtoss" button to launch the enemies. Doing this can make Silver more like Silver, and it can be set that it's impossible to do this if you can light dash, and vice verca.
EDIT: The Silver thing might not be so easy, but it might if you try looking at Senya's code and tweaking it so that you have a different stand sprite and an alternate pallet, and your target goes into a different state (looks like it's being held in air like enemies in S2K6).