I imagine that the Durango and Silverton and Maybe the Great Smoky Mountains Railroad are considered valuable assets while Mt. Ranier was strictly a rental and without operations, it would be a cash drain.
Sounds like a business decision to protect their assets and not someone elses.
The company is investing heavily in equipment purchases for the D & S (six diesels) without any operational revenue. Not hard to surmise that they didn't have cash around to subsidize Mt. Ranier until it could be operated profitably.