Something to think about though-- Mortal Kombat and Injustice really are two very different FG franchises. Look and feel, tone (level of gore), the way controls work, the way neutral is played, the amount of zoning--quite different. I suppose it's possible to truly like both equally, but my guess is that most NRS players above an ultra-casual level probably prefer one over the other. And some players have a very strong preference.
While it's nice having "something for everyone" in NRS fighters, I do think it adds to the problems with the community. NRS itself may be on a two-year cycle, but fans of a particular franchise are really on a four-year cycle until they get the next game they actually want to play. Which would be totally fine if NRS actually supported (in terms of patching, DLC, etc.) the most recent game from a franchise for four years. But what happens of course is that each game gets two years of support and then nothing ever again.
That fuels toxicity in the community in at least three ways:
One, when your preferred franchise is up, you've got all your eggs in that basket. You're counting on that game being everything you need to get you through the next four years. If that game turns out to be a disappointment (like MK11 clearly has for so many MK fans), it's such a huge crushing blow (krushing blow? Ha, only a little pun intended) to morale, knowing it will be at least four more years to get something better.
Two, it fuels a sense of urgency about patching. If the game were going to be patched for four years, people would probably be more tolerant of gradual incremental changes. But when you know the two-year countdown clock is ticking, you want to see changes come relatively quickly, and it creates a lot of impatience when it seems like NRS isn't "getting it" on needed fixes.
Three, it undoubtedly adds to the "players hating the game they're playing" phenomenon. Like if you're an MK fan, sure you'll probably play Inj because it's there, but it's really not your groove. People could probably tolerate that better if the game they enjoyed was still being supported, but when you've been cut off and the only game getting support is the one you don't like, it fuels bitterness and raises the toxicity of the complaining.
Anyway, who knows if this will ever change. I wish NRS would provide four years of support for each game, but maybe it's not economically viable to do so. I guess we'll see if and how the cycle changes this time, though again, MK11 is such a departure from what old school MK fans wanted that I don't know if will make a difference.
