Admin just doesn't care that much which speakers are allowed on campus. Like many progressive things students loudly champion, it's pretty immaterial and easy to just give in. It's not like it affects MIT's status or funding as a world-leading research institute.

By contrast, Senior House was a significant legal liability due to large, public parties with a habit of sending people to the hospital for more interesting reasons than booze. That, the institute has financial, practical, concrete reasons to care about.

It's unclear to me that SH created more liability than frats and alcohol, but maybe, and it was certainly the perception.