I'm not trying to "perpetuate" anything. Two family members have Moon in Capricorn, so I'm not pulling this out of thin air. Feelings from them tend to be pretty enshrouded. Your experience is apparently different. Fair enough. I speak from my experience.
Also keep in mind that perhaps you don't make them feel comfortable enough nor see you as trustworthy.
So before throwing all the blame on them you should consider your position too.
Sometimes people don't show their sensitive side to everyone but only a select few.
You can't possibly tell me you are emotionally expressive around every type of person right?
I understand we as people see things pretty subjectively but to make a good judgement it is wiser to observe them interact with others as well other than yourself,no matter how hurt you feel by those people.
I would advise you to avoid becoming prejudiced against them because that equals discrimination.And sooner or later if you hold on to the mentality "Capricorn moons are this and that way" you'll probably bestow on them a lot of blame or even avoid them without making a thorough judgement but basing it on your "experience".
Also people tend to be wrong in their judgements quite a few times in their life.We are not perfect or always right.
You can never know what a person truly is feeling even by observing them.Except if you decide to stalk them and witness some of their most private moments,your choice.
And if you have a problem with their "unemotional"-calculating nature it'd be best if you actually asked them what's up with it.It's a lot simpler than you make it out to be.I mean...who's better to answer your question than those people themselves?