You're just talking about the noise, right?
Thanks for asking - its worth clarifying what the "this" in "Long for the day when NYCFC has this" is.
There's kind of two layers to this.
Because, yeah, NYCFC supporters make a great atmosphere at every regular season game. The difference yesterday was having baseball fans fired up on a level comparable to an NYCFC game - but also filling the whole stadium. 45,000 really does feel different than 25,000, especially in a 45,000 seat stadium.
So yeah, that's just noise, I guess.
But there's another layer too, which I never really "felt" until last night, though other people have posted about it here before. And that is, that there really is a difference when a team has been around for awhile and has people who have been fans their whole lives, or fan relationships that go back multiple generations.
I feel a much more personal connection to NYCFC than to the Yankees. I always kind of feel like I'm at someone else's party when I go to a Yankees game. (In part thats because I grew up a Twins fan and don't really feel that great about cheering for the Yankees at all).
But I know many of the people around me in the stands have been rooting for the Yankees their whole lives. And I don't want to get to "woo-woo" about it, but I think, in a situation where there's a big game that really matters, you start to feel that kind of cultural weight and it just takes things to another level.
So this is in no way a criticism of NYCFC or its fans. But playoff baseball is just a different kind of cultural event than MLS right now. Will MLS ever be there? I don't know. Probably not to be honest, but it has its own charms and I'm fine with it.
(There are also bad things about long cultural traditions, like, I'm pretty sure our supporters would put a stop to some of the more obscene chants coming out of 203 last night. But that's another thing.)