The answer to your question is NO you don't have to care about people who don't care about you.

Going forward try to be more discerning about choosing friends. You can tell early on if someone is a caring person or a taker.

There are signs a person is a user/taker:

The person only calls you when they want something
They habitually do not return your calls or texts. (Not just occasionally)
When you are with them all they want to talk about is themselves and their issues.
They change the subject when you try to talk about yourself.
They expect you to go along with their plans but are a no show when it's something you want to do.

You can't change people, all you can do is protect yourself by choosing people who are good a caring people.