Let me put it another way. It's important for a franchise to fire on all cylinders, sure. But the fact that SS has a disappointing run doesn't necessarily weaken the chances for, say, a future Batman film or Superman film. Especially if there's been a reboot of some kind.
To be clear, I'm not saying that I think that THIS iteration of DC's cinematic universe is necessarily good or likely to survive. I think it will for now, but its days are numbered if they can't turn things around in another couple of films. Like, we won't get to a Flash film if Wonder Woman and JLA or Aquaman don't hit. Hell, we might not even get to Aquaman (which would be a crying shame because I LOVE the idea of Jason Momoa as Aquaman).
I agree. Just a fun topic to pick apart.