Like Haurchefant, Alphonse is one of those people that has semi-grown on House. He's an annoying little brat who's way too optimistic and sensitive, but he's... still a little kid. Who can bleed and be blinded. Somehow??? House has no idea what to think of that, bro. Stop. You're empty armor. Stop that. In any case, he has no desire to actively engage with Al on a regular basis and still delights in tearing into him with cynicism. If he made Al cry or actually give up on him, it might be a minor (admittedly Pyrrhic) victory, but it would be a victory. One he would hate himself for, but still probably lord over Al because House has Problems (TM). But until that point, he's ever so slightly concerned with Al's physical, if not emotional, well-being. Don't die or whatever.