I think sometimes we're looking for a little validation. We all want a little validation. It can come off as uncaring to say "why is this your problem". Maybe a better way to say it would be, "Yeah, it is annoying that coworker is always late. The important thing to remember is.........." I think we have to realize that it's nice to validate the person where they are, but also give advice, an opinion, or a dose reality when it's appropriate. We just have to be careful and use our best judgement.