I'm having trouble appreciating Kant's moral philosophy. According to him an action is bad if we can't universalize it as a maxim of human behavior. Under that way of thinking being gay is bad because if everyone was gay nobody would have any babies and that means you are willing the non-existence of the human race which would be a contradiction if you want to exist. So I guess bisexuality is okay but being a monk isn't. The reasoning seems absolutely bonkers if you are gay whether from choice or from nature there is no reason to surmise that you think everyone has to be gay. If Kants moral philosophy is so lame I must admit that it prejudices me against his whole philosophical system. Is there any reason why I should give Kant's ethics more credit?
I don't think everyone being gay would be a problem for the Kantian approach. Children can be born to gay parents, it happens all the time, and children do not have to be produced in the ordinary way through heterosexual relationships. In any case, willing the eventual non-existence of the human race would not be willing that the willer did not himself or herself exist, merely that in the future there would be no more people. The nice thing about the Kantian approach is that it does not allow for exceptions in just my case. I cannot say that something is wrong but it is OK for just me to do it, in just these circumstances. In fact, as we know many gay people in the past have been critical of gay lifestyles and oppressive to fellow gays, distinguishing between their own behavior and that which is publicly acceptable at a certain time, perhaps. Kantianism would be critical of such a strategy and surely rightly so.