The choice to become a Soulless Machine of Death is a highly personal one, and it's not something that can be entered into lightly. For most the choice is born from depression and the feeling that they are worthless as a normal functioning human being - but that kind of mental instability is stored in the one chunk of meat you get to keep, so those people are ultimately rejected from the program… which probably doesn't help them to feel better about themselves.
General Rosewater, who was deeply involved in the initiative from the beginning, famously and controversially compared it to the choice to become a Catholic priest - he said that there were some who took the vow of chastity in an attempt to avoid feelings that they were ashamed or afraid of, such as a desire to have sex with "other males, children, the pope, whatever". This was, he insisted, a doomed plan and did nothing to serve the priesthood - what was really needed was a genuine desire to dedicate yourself to service of the almighty that superseded any natural urges and distractions and that was (as the general pointed out) "mighty hard to come by these days".
Of course the analogy breaks down at some point because in actuality every major religion and ninety-nine percent of the minor ones had declared the whole process of converting yourself to a Soulless Machine of Death to be completely immoral which was hardly surprising considering "soulless" is right there in the name. Flaws in the analogy didn't stop the SMD's from adopting the practice of wearing white collars, which would have further infuriated the Catholic church in particular had it not been for the fact that they had long since hit their limit on this issue - even Catholic disapproval can only go so far before becoming exhausting.
In point of fact the SMDs kept to their vows of loyalty and chastity far better than actual priests, because a lack of loyalty resulted in execution and a lack of chastity was actually quite difficult when your reproductive organs had been completely removed, leaving you smooth like a Ken doll - albeit a Ken doll with terrifying integrated weapons systems capable of leveling a city block. This part of the sacrifice is what had led General Rosewater to make the comparison in the first place and was one of the main sticking points.
In the case of Jeremy Porter a lack of reproductive organs was more of a perk, as they had brought him nothing but trouble. For reasons that were not clear to him he had simply never been interested in sex - he worried growing up that he was gay, but after browsing through various types of pornography he determined that he was neither gay nor straight. He also was not aroused by animals, children, corpses, feet, or bondage. Certainly there were some combinations that he had not specifically investigated so it remained a possibility that he required a tied up dead underage male goat... but that seemed unlikely and distasteful. In the twenty-three years before his conversion the only thing that Jeremy had found that aroused him at all was the smell of carpet glue. He wasn't sure if this was some sort of miswiring in his brain, possibly related to pheromones, or if it was a deep psychological issue... had he seen his first naked woman while someone was installing a carpet?
In the end he decided it didn't really matter and his genitals were thereafter thought of only as an inconvenience, something that he had to apologize for or explain away every time someone took it upon themselves to fix him up with someone. He didn't miss them at all, and was far more satisfied with the heavy laser built into his arm.