I definitely think the SW Monorail is just a mode of transport. It doesn't offer any form of unique experience. People really only use it to get from one point to another. The park themselves don't even list it as an attraction, its under its own heading in Park Info.
If the transport incorporates a show or new scenes or views that aren't seen on foot, then yes I would class that as an attraction (Eg. Disney's train, DW's paddlesteamer, etc). An attraction is something go to a theme park to experience, I doubt there are many people that go to SW to purely just ride the monorail, or go out of their way to ride it.