There was no forcing. People voluntarily expressed their desire.
* Some people no longer wanted to work at Firefox if he was their lead
* Some people no longer wanted to use Firefox if he was their lead
Now, the organization can easily take any position here. They could say "Yeah, I guess you can't work here, employees who can't work with Brendan Eich. And yes, I guess you have to stop using Firefox, users who can't use product led by Brendan Eich" or they could say "Brendan, looks like you leave or we lose these people" or anywhere in the middle.
This is just people freely expressing their views and advertising how they will act. It is pure liberty and I love it for that.