I'm not sure... I've had the same experience you've had. (Except I haven't had any Spwith encounters since then.)

My gamer-sense is that he's a gift at the beginning to give you a tough-to-kill (30 crew) and therefore newbie-friendly escort at the start of the game, assuming you're clueful enough to find him and sensible enough to befriend him. I found him useful against those dang Sylandro Probes while my flagship was still wimpy.