Why do only they get to love and get to be loved?

Do you mean "Why do straight people think that only straight people love others, or are capable of being loved by others?" Is that why you think many straight people think LGBT people can't possibly be married couples? Do you think that is what's behind their certainty that LGBT relationships are all empty debauchery and sin? You think they can't (or don't) imagine that LGBT relationships can be based on love just exactly as their own are?

Interesting proposition. As to "why?" ...if this truly were the case, I would guess that they simply lack imagination. Most of us are not terribly imaginative, really. Not in any constructive sense, anyway. We can readily imagine people being worse than they are, but once we become adults and stop talking to invisible friends and fighting invisible adversaries it becomes very hard for us to imagine people being better than they are. That probably has a lot to do with it.

You have chosen to be gay. If you just did what nature intended you wouldn't have to worry about this question.

Many, many, many straight people do not feel loved. (Even if they are married.)

I know many gays who are good, loving people. They are loved in return, even if it doesn't include sex.

I don't get it.

what the hell are you asking?