I'm not sure why this is getting people so worked up. 1/4 mile distance between the transit station and the ticket counters isn't very far at all. Sea-Tac's design puts all the gates quite close to a very compact ticket/baggage area, so the overall distance from transit to gate is still a lot less than most airports that I can think of.

Also, I'm not sure how you could place the station any closer to the terminal without completely screwing up the airport and shutting it down for a year or so. Where, exactly, would you put the station to make it closer?

I suppose you could have put it at the N. end where the cruise ship baggage station area is, but then you'd still have a far walk to the S. end of the terminal, plus construction would have been more disruptive.