>>725262941 (OP)
not enough ongoing support, not enough content, not well-designed enough
they stop making new ones, which means you have to start from scratch in terms of building up a reputation, but you also have to start from scratch in terms of iterating and improving on what you did before.
of course other games are going to be unsuccessful if they release without any content like all the smash clones so far have. I've played all of them and they're insanely barebones. The best in terms of feeling like endless love and sweat and encyclopedic contributions was Jump Super Stars and then Ultimate Stars for the DS.
Both of those sold about 800k copies in Japan alone, and they never made any more or localised any new entries. But if they made another game of that level of quality today the interest would be enormous, even with the severely atrophied interest in Jump properties since most of their new titles don't really have the power their old ones did. But they don't make the games. Games just don't get made anymore.
But playstation allstars, nick, multiversus? These games have NOTHING to offer except a very basic core gameplay loop with very limited complexity and no support. They're incredibly unprofessional prototypes with none of the flood of different stuff to offer that smash games have managed to since melee. Melee was made in 13 months and it had a zillion trophies, it had adventure mode, it has event mode, it had stadium mode, it had a zillion custom fighting modes, it had endless pokemon coming out of pokeballs, it had items galore. Very very few of the smash clones have even a TENTH of what MELEE had, a game rushed out in a year on rigs with 64MB of ram and 8GB HDDs.