I completely disagree!
The two shirts are very different. The first one, worn by the girl, is preaching acceptance and tolerance - a wonderful virtue! The one about feeding Christians to lions isn't exactly advocating tolerance, and I'm assuming that isn't the literal opinion of most of the people who wear such shirts (and if it is then that degree of extremism really bothers me). Conversely I would assume that the "Gay? Fine by me" shirts DO represent the literal opinion of the wearers.
That's completely different in my opinion. I do advocate speaking up for ones values in a confident, composed manner. I just don't advocate creating unnecessary strife and pissing people off for no positive good.
I don't have a major problem with those shirts. I get that it's just a joke, and it is funny. I also get that one can say it's only "fair" given some of the horrible things the people being attacked by the "lion shirts" have said (I.E. "AIDS cures homosexuality" etc.). The distinction I'm making is that it's better to voice your opinion calmly, rationally, and compassionately, then step away from the issue and let it sink in versus engaging in a screaming match and escalating the situation. Minds and opinions aren't won like that. When people take the defensive they aren't going to question their beliefs and values. The sad fact is that the people in question probably won't in either case, but at least in the second scenario there's a chance, and at least you can say you're not sinking to the level of hate or needlessly hurting people.
Anyway, I don't meant to come off so strongly against said shirts. I personally disagree with them, and wouldn't wear them, but I'm not going to sit here and criticise people who do. I just wanted to make my stance, and distinction, known.
-Kevin