I really really really hate this, I dont think custom moves has any place in competitive smash and just makes smash 4 more of a laughing stock. I'm cancelling any plans I had to go to evo because of this. I wish there was a vote or something done because there is no aspect of custom moves that is competitive. It's random, now every character we have to expect different moves out of which changes match ups and changes our knowledge of each character. As long as smash has been around since 64 to Smash 4 when we learn the game we learn characters dilligently and I think this ruins that completely. It's really really sad, I really hope this doesnt catch on to other tournaments.
That's why we should allow custom moves, so nobody can pick a hard counterpick just because they know what a character can do. Think about it this way, everyone knows how to counter Mega Man's default moveset.
People know what the Metal Blades, Leaf Shield, Rush Coil, and Crash Bombs do. They can simply counterpick against that. Now, what if Mega Man can use moves like Hyper Bombs, Skull Barrier, Ice Slasher, and Beat?
It changes the dynamics of the match, and forces someone to put more effort into counter picks. Hyper Bombs act differently from Metal Blades. What might work to counter Metal Blades might not work against Hyper Bombs.
It's now no longer "Character A can counter Character B" because you don't know 100% what specials that character has. Customs also make characters like Ganondorf and Paluntina more viable.
I don't get the random argument either. The Custom Moves are in all copies of the games. It's possible to practice and figure out what the customs moves do and how to deal with them. There is nothing random about it!
Why are people so afraid of this? Marvel vs Capcom 3 lets you pick assists, and Street Fighter IV lets you pick ultra moves. This is the same idea, only on a bigger scale.
It also stops the game from being static in terms of matchups. Now, it's no longer "I know what this Link can do, so I'll just pick a counterpick to shut him down." Now it turns into "I don't know if this Link will have the Gale or normal boomaring, so I can't pick a hard counterpicks."
Custom Moves make the matchups more dynamic and less prone to just safely picking a counterpick. Now, some real thought and knowledge has to go into counterpicks. The only thing that is changed is the specials anyway. All normal moves remain the same.
Customs are in the game, people can practice against them and learn what each customs move does for each character. There is nothing random about it, and it can only make the game more intresting to watch since characters are no longer static and locked into a single moveset.