You're right. In principle. Dead right, I believe. Violence in situations like that should not be tolerated, and those that instigate it should be dealt with. Willie instigated it, and in spite of a lot of provocation Joe did not respond offensively. He stood his ground as one should with a bully. BB evicted Willie, and did not evict Joe. Seems right and appropriate. Joe may actually be a bully, I don't know, but his restrained response wasn't that of either a bully or a pacifist. All I've seen is a person with irritating loudness in the Diary room. In this case, he just did what was appropriate.
If someone charges you with blood in his eye as Willie did to Joe, you would have to either defend yourself or run. And there isn't anywhere to go in BB, especially if Willie is going to keep pursuing. And he would have, I think that's abundantly clear.
Joe had to get ready to defend himself. And I think that you (just my humble opinion) should direct your feelings about bullies to Willie. I don't know what they didn't show, but based on what they did show, Willie was the bully there, just waiting for someone to give him an excuse.
Willie sat there, brooding and cursing and generally ready to lash out at anyone, and Joe just happened to make a remark (after a number of very pointed remarks from Willie) that set him off.
The world nor the house revolves around Willie, and it's up to him to control himself and curb his violent instincts, just as it is up to you and me to control ours. And if he cannot, he should be out the door. For him to charge Joe like that was inexcusable and no fault of Joe's.
I do not know anyone who would not try to defend themselves against someone acting as Willie did. Well, maybe some would try to run and hide somewhere, but Willie at that point was an unguided missile, he would have gone off on someone else. Maybe a Gandhi could have talked him down. but we can't expect that from untrained people like those in the house. Not being a Gandhi isn't Joe's fault.
And by God if you ever maneuver me into the position of having to defend Grodner again, why I'll come across this table so quick...(Smiley face).