Sadly this happens with fighting games when new scenes emerge, it'll contain itself in years to come but because Smash despite being a long standing community is relatively new to the FGC being acknowledged only in recent years before that it was a large underground style community. What's happening between Melee and Smash 4 is what happened between Third Strike and SFIV, different approaches that people prefer.
The only difference is that SF has been part of the competitive scene for a while and the series has focused on it so the fans are used to the change of styles, Smash as a series has only started to focus on it in Smash IV so anything that doesn't resemble the face of the Smash community (Melee) divides the community. This is driven even more by the fact that with each new style and approach some fan favourite players can't make the transition to the newer game so they die by the older game.
I watched Apex, the difference between the two games is exactly like that between TS and SFIV with the newer game still being figured out but Smash 4 had some tense matches throughout sacrificing the speed of Melee for more diverse match ups. Just watch the Olimar player for a start, over time I feel SSB4 will be the better game much like SFIV went on to become.







