As I said, it's just my speculation... but I would assume for the same reason I can't hang with Dalja and pound back beers - FC didn't want it. I'm personally not a fan of when Omega get spawned - Who view me like family - Aggroing me on sight. The two camps on David are "He's still in Space" or "He...

David himself, as far as I know, never appeared in-game. There was an event some time ago ('03?) where a "Vision of David Marlin" appeared briefly. From my discussions with Clanners and my own speculations I'd say it's safe to assume David has, one way or another, made it to the Shadowlands since th...