If an NF really cares about you they will be loyal and commited, but you have to have buried your way deep into their heart to get that kind of commitment, or at least that's how it is with me. (INFP)
I'm very flighty friendship wise, and only a very few have ever mattered that much to me, recently I fly before anyone can become a true friend to me because I don't want to be loyal, to care or commit to anyone.
I have wanted shallow non hurtful and quick connections. The potential to be a deeper friend is certainly there, but you have to matter.
That's not true to me, but I always find the "NF" bunching wierd because not all NF's are anywhere near alike.
They're also hypocrites. Will leech onto you and depend on you for everything. For emotional stability. For friendship. Will want to share their whole life with you. They want to tell you all their problems. But as soon as you need them for something, it's never as important as when THEY have a problem.
That's an over exaggerated comment to make, if someone saved my life I wouldn't ever stop (I would hope unless they screwed it up) valuing their friendship. It's all about the value placed on the person in question. If you have connected with me in a way that makes me care, then the only time I will get rid of you is after years of you letting me down.
These are the type of people... You could save their life one day. And they next day they would end your friendship because they need to "find themself and start over".