Brave, articulate young man!

[OrphanPip]

While I have to identify with what the teacher was trying to do, I'm not sure it was appropriate behavior in a public school. Homophobic bullying shouldn't be tolerated, but wearing a pro-gay rights t-shirt to a class is kinda inviting discussion, and when you invite discussion differing opinions should be tolerated. When I was in high school the biology teacher opened the floor for the nature/nurture debate about homosexuality (gay marriage was just recently legalized in Canada that year), and in a predominantly working class neighbourhood with a lot of children of Caribbean immigrants, you can expect that a lot of anti-gay, often religiously motivated, opinions were expressed. The teacher responded with debate not punishment, which I think is the appropriate response.

If someone in that class had started insulting another student directly, or using slurs, then kicking them out of class would have been more understandable.