It’s interesting that I can read your question two ways. Are the people like your parents or are you like your parents in that question…? 
I have no idea if this is relevant or not but it just leapt out at me.
I can say that I totally get your frustration and disappointment with both of those scenarios. You had invested some emotion into both those folks and what they gave back was just flat and devoid of any real heart connection in my assessment. And that can suck for sure. When that sort of thing happens with me I guess I just remind myself that nobody is under any obligation to behave in a way that I find ideal. I can’t control that sort of thing. And then I just kinda drop into a ‘right distance/right depth’ sort of frame of mind. I can say that I’m not always as easily successful at navigating that sort of thing as my response might indicate but I’m pretty good at it most of the time I think.
And I’m inclined to agree with Norene that there would be no real benefit for anyone in this situation for you to explain your behaviour. I think that sort of explanation is reserved for people that actually connect with you in a respectful way…not that I’m suggesting you don’t explain as a way of punishing them…(I’m shunning you because you are not worthy of my attention!! lol) …but you’ve already invested emotionally into them and you got a very clear communication of how they respond to that. Don’t throw good money after bad so to speak, in keeping with the ‘investing’ metaphor…