The "service charge" is typically applied as some percentage of the room rate, which implies that it has *something* to do with the room, whether it be maid service, maintenance etc. The more expensive (better/larger?) the room, the greater the service charge. Definitely appears designed just to charge more for the room.
Not saying I agree, but at least with a "resort fee", its typically charged as a flat rate by the room or guest which makes it easier to justify as a fee for that guest using the facilities.
That said, I do think they'd be better off just wrapping up fees into the room rate rather then angering guests and trying to make a distinction between the room and resort.
Seems the consensus is that the service charge should simply be looked at as a room rate upcharge. Disappointed that Hyatt has taken this approach.