By this can I assume you are into forced procreation? At least through social, or possibly medical pressure. Are people who choose not to have kids mentally I'll?
Hat analogy works in my favour. Having no legs makes it hard to operate in society. Not having kids does not make it hard to operate in society. Your own examples are defeating you.
The perenity of your society depends on those who procreate. If its members can't procreate it's definitely an handicap for the society. I'm not sure why your trying to argue that.
Procreate - and then have that offspring be competent enough to carry the torch for another generation. To my knowledge it's never been done without a solid nuclear family foundation.
I am arguing against saying everyone is required to procreate. Your premise only works if you want enforced procreation. Your point is irrelevant if it isn't required.
Societies, yes. Individuals, no. I am saying something is not an illness until it imparts your ability to function in society. You say something is an illness when you think it is icky