Sorry if you've talked about it earlier and i didn't see, but I'm kind of interested on why you think there are too many third parties.
Personally: I was a Nintendo kid. Never owned a PlayStation of any kind until I was in my 20's, and I've still never owned an X-Box, so the Nintendo history is the stuff that means more to me. While I can respect their place in history, guys like Ryu and Cloud had zero influence on my childhood.
Roster-wise: As was brought up by someone else just now, the fact that the "big" Nintendo star are already in means we can dig into some more retro/obscure/niche fighters, and I love that kind of stuff. Suddenly throwing open the door to Third-Parties and making it a "gaming" crossover means that those niche characters are totally irrelevant now. Why add the protagonist of a beloved but forgotten 90's Nintendo series when Sonic/Master Chief/Laura Croft are the table?
I actually am not against Third-Parties categorically. It happened more gradually.
- "What a weird choice! I love how out-of-place and random he is. A cool guest character"
- "He's super-iconic and him and Mario were big rivals, so that makes sense. He fits in nicely with the cast."
- "Sweet. Another retro icon"
- "A little odd, but he's one of the original gaming characters, so I can dig it. Four guests in a roster out of more than 5 is more than reasonable."
- "...OK. I'd rather someone else, but he seems alright."
- "...I guess some people will be excited"
- "Seriously? DLC has been such a disappointment."
It wasn't really until DLC finished that I got actively annoyed with how many there were. And now it's opened the floodgates to lobbying for every JRPG protagonist and Twitch-friendly franchise under the sun, which, again, as a fan of mainly classic Nintendo, is mildly disheartening.
Still, not everyone shares that view, and I get that. It's just the way my gaming history and the evolution of the series has shaped my perspective.