Seriously, think about the children.
Thirdly, it’s unfair for Tuvix to exist considering the ramifications of what it means for not just Tuvok and Neelix, but for the crew, their friends and families as well.
Tuvok would never condone being merged with anyone, especially when it meant being taken away from his wife and children. While Vulcan’s get a bad rap for being emotionless, that’s not true. In fact, Tuvok has great emotional respect for his wife. When going through pon farr Tuvok rejects the idea of the holodeck when presented with it as an option, as he’s under the assumption that Tom Paris wants him to just pick any ol’ gal to conduct pon farr with. Yet, when Paris says he can do a complete duplicate of his wife, Tuvok agrees. Why? Because his love for his wife is so powerful he’d rather go through the pain of pon farr than disrespect her. So with that in mind, why would Tuvok consent to anything that would see him be definitely removed from his family’s life?
Neelix, to his creepy credit, is in love with a three-year-old. (Seriously, what was even the Ocampa?) Granted Kes aged liked a dog does, so she’d be in her 20’s by the point of the series but still. Kes is just as affected as anyone else. She even says she doesn’t love Tuvix and wants the man she does love, Neelix, back. As Tuvix was a science accident and not a sentient being born to a family, what right does he have over someone like Neelix?
Most people say that Tuvix was more likable and that they felt for him when he was begging. That’s unfair. Just because he may be more popular or more likable than Neelix and Tuvok, doesn’t give Tuvix the right to exist in their stead. You don’t get to just pick and choose which parts of a person you like in order to have a perfect person.
With Tuvix around, families and friends will have to mourn the death of their loved ones while Tuvix, who is loved by no one, not truly, gets to continue to exist as a weird and creepy amalgamation of two wholly different begins. If kids have a hard enough time with a step-parent, imagine trying to explain to your children that your father is now one-half of another being. It’s not natural and it’s not something that’s easily able to be processed.
Tuvix bore the responsibility of this situation. The only honorable thing would’ve been to go willingly, to ensure children didn’t have to needlessly lose their parent.