You can play this game with literally any group. If all fraternities have to wear the burden of ritualized hazing, racism, and homophobia then all sports have to wear the burden of violence, bullying, educational misconduct, misogyny, and chronic sexual assault.
You're absolutely right. Look at things like the NFL scrambling to clean up the Ray Rice mess and other domestic violence issues. All NFL owners and players have a responsibility to clean that crap up even if only a few bad apples are a problem.
Duke lacrosse, for example, absolutely deserved to have their season cancelled even if not all the players were involved with whatever they were doing. It was an attempt to genuinely change the culture that you won't see from IFC.
If IFC immediately pulled their nationwide support for SAE, it would be a sign that they can support their own. KSU should kick them off campus (as this is clearly an nationwide problem), but they really can't because they already let so much go on.
All message boards have to wear the burden of bullying, racism, homophobia, misogyny, religious bigotry, and ageism. I have a feeling your stances on these groups aren't as strong. I'm guessing you aren't willing to off sports and communication via the world wide web.
The difference is message boards don't have a nationwide infrastructure designed to support and police each other.