Oh, I definitely agree, but I think the fact that the monorail trains are all more than a decade past when they shouldve been retired and are (more) headlines waiting to happen at this point while Disney experiments with gondolas as the next big transportation wave of the future of the past tells us everything we need to know about where they're at internally for transportation initiatives.
But I also think that Disney, for all that it is a private enterprise that can do what it wants on and with its own property, is not immune to bloated US transit construction costs. (And I'm generally unsympathetic to the argument that nothing should be built until we bring costs in line with our world peers, but on the other hand, Disney isn't currently choking to death on car culture, so.) And while I can absolutely fault them for the current state of the monorail, I cannot find it in me to fault them for choosing not to build more of it when the bus system (present issues aside) generally works about as well as you can hope for a bus system to work.
Frankly speaking, even as a staunch advocate for real transit solutions, I probably wouldn't sign off on running rail to every corner of the Disney property at the current going rate if the choice was mine. ($107m/km as of 2019 - a spitball estimate just based on how many points of interest there would be to connect says the going rate to establish WDW Metrorail is currently right around $2.5 billion, or about 100 years of funded bus service.) And it's not like Disney is currently lighting billions of dollars on fire for a useless interstate expansion that it could easily redirect towards transit instead, nor are thousands of guests dying annually at Disney due to the negative externalities of widespread single-occupancy vehicle adoption.
I really do hate to admit this, but Disney not building more trains is probably the right decision.
EDIT: Had a look at some other bus system operating budgets and decided I lowballed how many years of bus service would equal the $2.5bn investment on the balance sheet. It's probably 100, not 1000 - which, still.