They couldn't even give us that scene for Kes and Neelix and they actually were together and then broke up!
They couldn't even give us Chakotay asking Seven out, or vice-versa. They just slapped it in our faces and we all went
Janeway did have some romantic relationships, but they were after she found out that Mark had moved on back home. Kashyk I think was partially the product of her trying to manipulate him and he trying to do the same, and they somehow fell in love in the process or something strange like that.
Jaffen (from Workforce) was another instance were there were different circumstances. For one thing, Janeway's memories had been tampered with, and I think that allowed her to be more comfortable with relationships because she was in a different working environment (shame they didn't actually have her in a relationship with Chakotay as originally planned).
Sullivan... I don't know what to say about that. People get lonely; it can be very lonely in space. He was something entirely different from the world around her.