The Skyway closed because:
Guests rode in an unsafe manner (shaking the cabins, opening the doors, etc.)
Guests liked to spit out of the cabins onto people below.
The park was under pressure to make it handicap accessable.
(True, many rides are not strictly accessable for handicapped guests, but most will accomodate a rider who can leave their wheelchair to enter the vehicle. Not Skyway.)
And the last reason: Capacity. The Skyway had the worst capacity in the park, besides 20k. Added to that, it was very labor intensive, requiring 4 CMs at each end. The lines never ended, extending to the area near Small World most of the day.
That left a lot of folks waiting an hour or more for a short, uneventful ride. Anyone remember Discovery River Boats? Same deal.
Oh, yeah, one more.
Lots of people complained about the trip being only one way.
Complaints + low capacity + no handicapped riders + unruly guests = extinction.