Trust me: Everyone is selfish. They just manifest it in different ways. That person who gives everything he has for charity is being selfish.
Most sane people do things because it satisfies something in them. The one who is very generous is getting something out of it. Even when dealing with selfish people, it's good to identify what they are getting out of it.
This is an obvious and trivial observation which misses the point of my statement. In my experience, the vast majority of NVC practitioners use NVC as a weapon to manipulate others by righteously invoking "universal needs" while avoiding introspection into their character flaws.
Edit: I acknowledge that my "anectdata" leaves out people who practice NVC without giving any overt indication of it. As with vegans, there is probably a selection bias for other personality characteristics. (The best vegans are not as obviously vegan)
Generally, people using the NVC template that you recognize are "beginners". So your edit is probably very relevant. As I said in another comment: Actually observe those who communicate very well in stressful situations (very well = both parties not upset after the fact, with some resolution on the issue at hand), and you'll find their approach is fairly similar to NVC - they're just not using the templates your recognize.
Trust me: Everyone is selfish. They just manifest it in different ways. That person who gives everything he has for charity is being selfish.
Most sane people do things because it satisfies something in them. The one who is very generous is getting something out of it. Even when dealing with selfish people, it's good to identify what they are getting out of it.