I always find it interesting when people defend a certain phrase as not being insulting — but they are not members of the group the phrase is argued to be insulting to.
Let's ask gay people if they find the phrase "eat a d***" insulting, not straight people.
At one time, some racist white people tried to argue the N-bomb was not racially targeted and could be applied to white people. Well, that argument didn't last and I don't think too many black people (some feel free to correct me if I'm wrong in this assumption) agreed with it.
Don't assume that a phrase isn't hurtful if you're not part of the target group that some maintain it's hurtful to. White people shouldn't tell black people what should or shouldn't hurt them; straight people shouldn't tell gay people what's hurtful to them.
I think it might just be common human decency.