What I don't understand is why people can't just be honest about this. If you ever point out to someone that based on their actions, it is obvious that they don't care, they usually get defensive and take it as a personal affront, despite it not being a reflection on their character in most cases (it's not a moral failing to not care about someone, especially a rando that you have no personal investment in).
Personally I have never told someone I cared about them unless I 100% meant it, which means that I have only ever said this to one person on this Earth, for whom I would've dropped everything had he just said the word.
Caring about someone is a burden. It takes time and effort. It's not something flippant -- you can't just drop in and say "I care" and then GTFO, which people don't seem to realize. To quote one of my favourite shows, "the big gesture isn't enough. You need to be consistent, you need to be dependably good. You need to do it everyday." If you don't care, fine, but at least be willing to admit that instead of being two-faced about it.
/rant