Regarding the topic OP, I can't say I agree.
The Super system is both really divisive (from a casual standpoint) and really limited (from a competitive standpoint) as it was implemented in PSBR. Doing a sequel in the same style would be pretty risky since, again, it wasn't well liked by most but there's also the problem that there's no immediately obvious way to improve the Super system like there was for Smash from 64 to Melee.
I actually think the Super system may be a dead end, in terms of gameplay systems for a platform fighter to take. It could work, but I think it'd be very hard to do so, and in a way that's accessible as Smash is (i.e. the Super system is very, very hard to balance for both 1v1 and FFA). As a platform fighter fan, I would personally love to see the Super system be explored, but as a PS fan that would want a sequel to succeed, it'd be much better to either do something entirely (arena fighter, or traditional fighter) or to actually go all-in and do the Smash system, probably in a way to attract fans of Melee's gameplay.
I would love a PlayStation crossover title but I don't really think a PSBR2 that directly returns to the Super system would necessarily be a good idea.
Nintendo made some pretty good Smash Brothers clones:
1) Ganbarion isn't Nintendo. They also work for Bandai Namco
2) You actually meant to post this game (as the developers of this title, GameArts, had a hand in making Super Smash Bros. Brawl)
Whenever I read posts like this, I feel like it's from people who don't understand what makes Smash good. Smash has a level of attention to detail, polish, and overall cohesiveness that I think comes from Sakurai's direction, as evidenced by his ability to create each game utilizing different teams and still maintain an insanely high level of quality. It goes beyond just having a dope roster of characters and a high budget.
People really overestimate how good or high quality a Smash clone needs to be.
Most Smash clones are just genuinely trashy (one game I've played couldn't even implement hitstun properly) or go for dumb, gimmicky not-Smash systems. If more games were just better at playing like Smash, or had actually decent derivative gameplay systems (like Jump Ultimate Stars, which was pretty good, and was only hampered by a Japan only release), they would sell better.
In fact, for those that have been following these kinds of games (platform fighters), the shift has already started to happen with titles like Rivals of Aether, and other in-development games aiming for the Melee audience.