As for Neelix, a lot of the dislike stems from his extremely creepy relationship with Kes, who is only 2 years old at the beginning of the series (Ocampans only live to be 9 years old).
If Kes and Tom had ended up together, would it have also been seen as creepy? Despite being younger than Neelix (relatively speaking), Tom would have still been way older than Kes.Kes (at two years) was the equivalent of a young twenty-something adult, not a child. Neelix obviously didn't want their relationship to end and his reaction to it's conclusion was not atypical. But he handled it better than some.
Since her species lived 9 years, I think she was the equivalent of 20 something at age 2.
In my opinion, I think that he is probably more depressed than anything else, given that he had led a rather tragic life. I think that his "outgoing" and "cheery" personality and likewise traits are probably a front to help mask and project a false sense of happiness. I don't think that he wants others to know that he is depressed. Of course, this is just my opinion and my interpretation. I have not seen the series in years. I could be totally wrong.
Neelix lost his family and his home world. I really think the Voyager family became people he wanted to give his caring to and maybe gain some self-worth back in the process. Under his colourful exterior was a lot guilt about not serving in the war. Survivor's guilt I suppose.
I think he had guilt about not serving in the war. And also about not being with his family when they died. Guilt coming at him from both sides.
