What he said was stupid and disgusting. People sometimes over-estimate the amount of latitude the organization they work for will give them to do this. The technology industry is taking baby-steps towards actual inclusivity and diversity of thought -- and not this dumbass "I want to be free to say stupid offensive shit with impunity" flavor of "inclusivity" that people around here seem to champion. That is a Good Thi…
If your "inclusivity" stops at Stallman, it seriously lacks performance. You use the wrong word. What you desire is conformity. edit: Additionally, because I think this isn't obvious here, Stallman opened up the knowledge about software to the whole world and put energy in keeping it that way. Anyone was able to profit from this.
The flip side of diversity is inclusion and those actions ran counter to MIT's own policies on an inclusive workplace (if you want a legalistic justification for him needing to leave).
At the same time, though, diversity can't be a cover for actions that are harmful to the larger community. Many places in the world still have strict social pressures against other sexual orientations. Saying you want diversity and inclusion, but excluding gay people—that would be conformity. However, being around queer folks does not actively harm the workplace environment or social culture. However, asking new female students if they want to go out with you, or being grossly insensitive to the plight of sexual assault victims is harmful to a non-trivial portion of the lab.
I would argue that, while RMS is a rightfully accomplished activist and computer scientist, his removal at this point in time makes CSAIL a more inclusive place. Those who might stay away because they're worried about his reputation or hurtful insensitivity—say, young female students, often underrepresented in science—may be more willing to work there.