I'm glad all the aviation experts have weighed in now.
Not that I've ever handled hundreds of inflight emergencies, including disoriented (hypoxic) pilots, or pilots encountering IFR weather when they're not qualified or trained in handling it. I'd say that a plane without a pilot ranks right up there as about as rare as getting struck by lightning while being bitten by a shark.
Just shitting out a pilot to talk him through anything isn't a guarantee.
We don't have some magic roster of pilots sitting next to the scope.
"Hey bob, it's jim. Yeah I got another nutjob who needs help landing a plane he stole."
Some shifts we have several qualified and current pilots around, other shifts not a single one.
The indicated glideslope for a given approach is an ideal, assuming - among other things - a pilot who's actually landed a plane before. Q400 needs ~4300' at max landing weight, (granted, I don't know how much of that requires reverse thrust, but he's also likely way under max weight) and SEA has a runway just shy of 12,000'. You can miss ideal by a lot and still have plenty of room to stop on that. Shoot for touchdown on or beyond the 2000 foot mark and he's still got more than double the maximum stopping distance, plus if he's low, there's still room to land "short."
You're assuming that the "pilot" wouldn't push the plane too low too far from the runway, to the point where you're not coming back up far enough to make the runway.
dumb
*expletive deleted*ing
idea.