What are your thoughts on gay rights?

I was on Facebook last night and I saw one of my friends post about how he doesn't agree with Macklemore's song Same Love.

 He talks about how teenagers are allowed to wear shirts like this:

 

But can't wear shirts that say: "Our school has embraced what God has condemned." It really bothered me that this post has gotten over 60+ comments that are literally PARAGRAPHS. I mean yes we all have our beliefs but do we really have to preach it? ESPECIALLY ONLINE. My friend is a great person and wouldn't try to get everyone to believe what he believes in but he's also bothered that they talk about this topic in class. Any thoughts?