Introversion or Passive-Aggression?
THE BEST WAY TO figure out which it is is to ask him in a way that doesn't come off as blaming or threatening. The tricky thing about asking for more emotional connection is that it's not really something someone can produce. There's no manual for creating emotional connection, and moreover, if you try too hard, your mind will be absorbed with thinking and self-consciousness which prevents emotional openness.
Opening up emotionally has two components: 1) the listener creates a safe environment for the other to open up, and 2) the other finds courage. Courage has to do with dropping all facades and being honest about whatever it is you're going through. It's being vulnerable and in-touch. The safe environment has to do with letting someone know that they don't have to be ashamed of who they are, and that if they reveal who they are--i.e., if they develop courage and share with you what they're feeling--they won't feel judged and won't have to defend themselves. There's nothing worse than being vulnerable and having someone start asking critical questions or try to give you unsolicited advice. Sometimes people just want to be understood and heard.
So back to you...as much as you want more emotional connection, you need to ask yourself how that request is being framed and received. Ask him. Is he taking it as a demand? Does it make him feel unsafe and inadequate (highly likely). If it does, just listen to him. Hear him out. Listening and making space for him is where the emotional connection grows from. There's nothing wrong with wanting to be emotionally connected, but you do want to ask yourself whether the means you selected are the best means available.