INTJs are the most independent of the 16 types. Relying on others, or accepting anything from others is sometimes difficult and we can go to absurd lengths to be entirely self sufficient, needing nothing from others. Being generous or helpful in a constructive sense (not in an indulgent sense) is far more in our comfort zone.INTJs seem to need constant sparring partner even in the romance department. However, they seem to prefer a balance of challenge and submissiveness in a partner. I'd say they seek understanding of their feelings and ideas from a partner they respect, though they don't need validation from that partner. They enjoy competitive discussion, but hate unproductive competition. They are highly independent and self motivated. However, they often shy away from stepping outside what they value for anyone.
I think compromise is harder for the INTJ because they are often certain and staunch in their judgments. They have a clear picture of what they want and how to achieve it. Anyone coming in to tell them what to do, how to feel, or what to think is not going to get very far. However, they may lose out on enjoying a strong personal and more emotionally intimate relationship with a partner because they are focused only on how things are understood to their own minds, or only on the practical or physical needs, and later neglect the emotional needs of their partner. This doesn't mean the INTJ does not have emotional depth. They just tend to be more selective about who gets to see that part of them.
INTJs seem to get their validation from within, from the logical, intuitive part of them which strategizes. They don't look outside for external validation. Rather, they look for affirmation. Unfortunately, this means when someone needs validation from them, they're reluctant to give it because it's not something they necessarily need from others to feel confident in their beliefs or decisions. They believe what they do regardless of what others think. This is likely why feelers can seem like complete fuzz balls to them, because emotions are things to be controlled, managed, and cordoned. They don't like being subject to another person's judgment. They don't see their feelings or emotions as existing for external observation or validation. In their mind, "my feelings, thoughts, and beliefs are my own. No one else's. No one gets to decide if they are ok, except me."
This is what I've learned about INTJs. I have family members who are XNTJs, so I've seen this all my life.
Dog people seldom are at ease with INTJs, whereas cat people can handle our independent untamable spirit.