I don't see him as a child...I don't see myself as his mother...I think I've perhaps misrepresented myself with the nurturing post. My conception is that everyone enjoys being nurtured from time to time. Families that are healthy do this for a life time, appropriately nurture one another that is. However, no one should have the "dignity" to interfere with others' ability to even enjoy their own home. In reality, how is asking someone to go to bed when he is tired treating him like a child? Isn't allowing the person to sleep where ever he or she chooses and not having the expectation he or she be responsible and considerate toward others doing more to treat the person as a child?
I don't excuse any of his behavior...none of it. I am cognizant of his upbringing, but I don't condone repeating it, ever. If his father was abusive towards him, or his mother failed to nurture, I expect him to recognize how that affected him and not repeat that for his children. In reality, we are both further from the abuses we both experienced as children, but clearly there is more work to do.
I think context is everything...maybe you are fine if someone is taking up the favored room in the house and believe progress is ignoring it and finding another place to spend your time...to me it is limiting my opportunity to enjoy my own home. I don't see how this is any different than a room mate or other member of the family walking in and turing off your music to watch TV without asking if it's okay. There are basic standards of consideration that can be expected from everyone.