This is an informal fallacy, "letting perfect be the enemy of good." You have to feel out people who are doing this and try to determine what their angle is. Usually they have one, some kind of asinine hobby-horse or ulterior motive, and you need to figure out quickly if they're arguing in good faith or not.
Because usually they're not, and inevitably you'll find that as soon as you're done addressing one point they've moved the goalposts somewhere else.