That he never learned from any of the many, many, many, many incidents of annoying Tuvok makes him either a jackass or someone so damned stupid that he's far worse than a regular jackass.
And exodus, neither of those is really the same case at all. First of which, "among friends" is a key part of that first point which wasn't the case in VOY. If someone I didn't like to start with started calling me "Mr. Whitey", I'd have to fight myself pretty hard not to slap him silly. Secondly, as far as the food point, once you tell them that, they probalby won't ask you again. This is in contrast to Neelix who never learned anything from his interactions with Tuvok.
How would he learn? How many times did Tuvok ever correct him, or point out his error? (legit question, as I don't really feel like sifting through ~170 episodes of VOY to see how many times Tuvok called him out on it). Tuvok mostly ignored Neelix's mistakes, and Tuvok shows no discernible emotional response to work from, which is what a guy like Neelix would probably pick up on. Neelix is a friendly and diplomatic guy who probably tried to take an interest in everyone on the crew, since he was the chef to all of them, and de-facto "moral officer". Vulcans are a very different species to humans, and different to anything else he'd be used to dealing with in the DQ. What works for humans isn't going to work for Vulcans. So he learned from experience. When that experience gives you no feedback, you're going to continually fail. The "Mr Vulcan" thing was a silly nickname, but he never used it to be a jackass.