IIRC the monorail was to be completed in phases with either the next phase or one after to connect to the airport. There are also plans for expanding the airport which may make a difference with planning of the monorail to the airport. I don't know if funding for future phases have been approved.

I'm not sure of the current ridership but with the fares being at $5 one-way it is a bit steep especially since usually you need to do a bit of a hike to get to a station.