All those games failed for numerous reasons. KI was on a system like 10 people owned, and by the time it wasn't it was 3 years old and pretty ugly. KoF had no chance to recover after those reveal vids and how ugly it was became a meme in the mainstream (and no one historically playing KoF in the west anyway)... and Skullgirls is an old as time indy game that came out around the same time as SFxT, Soul Calibur V, MvC3, MK9 and numerous iterations of SF4.
Injustice 2 on the other hand is coming out when the only other big game right now is SFV which a tooooon of people are unhappy with, and are looking for other options. Yet this game that everyone hates still had 40k viewers on twitch a couple days ago.
To say that kind of exposure is meaningless to a triple A game with a big license that is already selling out of pre-orders is crazy to me. Injustice 2 can't be compared to Skullgirls or KoF for so many reasons.
I'm glad you brought up memes, because that does play a big factor.
A prevalent meme that has indoctrinated thousands of would be players of other fighting games is that SF is the "correct" way to play, and that everything else is cute but it lacks "fundamentals," so you can't take it seriously. The character that shazzy plays? There are plenty of people who actually think that.
So when a game comes along that tries to do something different, and may not play in the traditional way, it gets its fair share of detractors who don't actually play but just apparently know well enough that it's for mutants and anytime it's on stream it's an abomination.
This is your average fgc fan when it comes to a game that doesn't have an established, nostalgic legacy or "normal" gameplay. The factors you mention play a part, but none bigger than this. No word of mouth can save a game from this.
I2 is going to triple the sales of SFV within one year. It's going to be better reviewed than SFV. It's going to be played by more casual fans than SFV will in its entire lifespan. Unfortunately, no one can solve that initial problem of it being wacky, which means there's a large population that already has its back turned to it, top/known player opinion be damned.