I think there is a learning component to empathy in the sense that, like say any other ability, it rarely develops past a point without practice and example.

We're probably all wired for empathy as humans(and those who aren't, are born with some condition) because it makes sense as social creatures and as a species that thrives by sticking together and cooperating and forming bonds.

I do think that, depending on each person's personality and the smallest of details in their upbringing and general experiences, someone who grew up without making close connections with others, someone socially isolated and "different" can very well just not really know how to channel that capacity for empathy, what to do with it so to speak, how to feel it and act on it. It's not that it isn't there and of course everyone has different levels of it, but it would make sense that someone who is socially inexperienced and hasn't connected much with others, could feel/appear less empathetic than they could be.

Think about it, for ex, it's shown that because of gender stereotypes and roles, girls are encouraged to develop their emotional and social skills/awareness, while boys are discouraged from it and taught they should repress their emotions because boys aren't supposed to be emotionally sensitive. As a result, it's not really that men don't feel intense emotions and cannot be sensitive, it's that a lot of them end up repressed and stunted emotionally, they lack the skills to properly identify, feel and express their emotions. What we call emotional intelligence and social skills, like empathy, are things we're wired for but there is a learning curve, you do need to practice and develop these skills.

Sure, no everyone is as strongly empathetic as others, just like we all have the same needs but on different levels, in different forms. But empathy is not absent if you don't give a damn about kids starving in Africa or something like that, the way you react to those things are influenced by culture and general knowledge and so on. Empathy isn't absent just because you can't empathize with everyone and everything, because empathy involves a certain degree of intellectual understanding of the situation someone is in, a certain degree of tolerance and so on.