I would imagine that insight into people would help develop, maintain and strengthen relationships. Infact if there is something I would wish for in any relationship it is insight into the other person. Something that should be noted is is that no one would like to have their vulnerabilities exposed/discovered. So it is best to not express your feelings on the vulnerabilities of others but use your insights to read, secretly empathize and not to step on toes.
Of course I could imagine that extremely deep insight into others would make you feel as if you are dealing with immaturities. Now this could hinder your need to interact, lose faith and leave you with feelings of frustration.
I totally disagree with what @highlander had to say.