(random thoughts)
About smash 4 having limited movement options (which is disappointing):
One of the fundamental aspects of any nintendo game is the gameplay and the control that you have over your character. Also, aside from how you "kill" your oponents, movement is the thing that differentiates smash from other fighting games the most. Because of how you can freely move around a stage in different ways + using platforms, you can approach your opponent from many different angles and ways. Its a really "open" fighting game...
Thanks to all the control that you had over your character in melee, you could move around the stage in a fluent and fast way (both in the ground and the transition from ground to platforms, from a platform to another and from platforms to the ground). Having that control was just fun. I am just talking about moving your character around and nothing more.
Movement options and the control that you had over your character were
really limited in brawl in comparison with melee. So, that limited the game.
I think that that alone is enough for being against the change in brawl and (supposedly) smash 4. Now, if you were not aware of those movement options from melee (like myself until a couple of years ago or so

), this problem does not exist for you (i am not saying that it would be a "problem" for you, only that it could be).
Marths mobility in melee is so cool
O). Its not in brawl, and it seems that its not in smah 4. (i am using marth as an example)
Still, i am going to play as much smash 4 as all of you!! (i easily played more than 1000 hours of brawl with friend a loooot of years ago).
I made this post because i think that it would be easy for anyone to see that change from melee. I mean that, if you didnt know about the "advanced" melee game when you played it (i didnt back then, but luckily i still have my gamecube with the game), you dont need to learn all about that crazy game to begin to see by yourself why many people dont want to change from melee. I think that using just some hours to learn and try those movement options would be enough. You dont need to go for something as crazy as fox/falco to see it. Marth is a great and easy example ;P