Syn, I'm just wondering if you feel that female cats should be left intact? And, if so, have you ever lived with a female cat in heat? Many times, if a female goes into heat and is not bred, she will continue in heat with dire consequences to herself. If she breeds, she then risks all the complications of pregnancy and birth, and can produce at least three litters of kittens per year.
Unless there are homes available for those kittens, they will either be "put to sleep" or will have to forage on their own and face all of the dangers out in the "world".
Sexuality to cats is not really an issue. A vasectomy for a cat that will leave him infertile but still responding to hormones is not really fair to him or to his people. You will have a cat that constantly fights, constantly sprays, and is quite likely to be aggressive--not only to other cats, but also to humans. I think that a vasectomy is pretty much a death sentence for most cats.
Anthropomorphizing a cat's feelings is not exactly the best way to go. I've had unneutered cats when I was a child (speutering was not considered necessary back then). I remember seeing my cat come home with half his ear ripped off, and bearing various gashes and cuts. He was unpredictable towards humans, and he didn't live long. Conversely, the neutered males I have now are happy, playful, affectionate, and live long, healthy lives (one lived to be 22). I never saw them mourn their "manhood".