Starcraft also had a ton of problems.There's been plenty of tweets from EG/Capcom guys complaining about the disaster that was Killer Instinct.
Smash was the least pathetic but it was still delayed due to the same reasons. The incidents affected everyone in the FGC not just the Injustice community.
Maybe you were referring to the COD tournament. Then in that case you are right. It seems like only the FGC tourneys had huge problems. Every time I tuned to watch some COD everything was running very smooth, non-stop stream action + interviews before an ad showed up. No delay or apparent problems whatsoever for the rest of MLG. edit: Forgot about StarCraft. Yeah apparently they had problems too related to internet issues mostly but still a lot of delay for them.