$20 mil...when it was built originally it was around 1 mil a mile...it's probably closer to 10 - 15 mil now. So, we get a mile and a half of track.
I'd love to see an extended monorail, but frankly, they are having trouble keeping the ones they have now in serviceable condition. And, part of that, is that it doesn't generate revenues. Transportation is a must, but is cheaper/more efficient with the bus lines.
Do I like it? Not really...but, it makes sense.
The monorail vehicles are basically just busses anyway, and they have maintenance failures and breakdowns, but are harder to service (they need special dropdown tracks and special parts)...and when they do, break down that is, and they DO break down...it's hard to get people off and back on. A bus breaks down, they pull up a new bus (which can generally be emergency routed there within 10 - 15 minutes), block off a lane of traffic, and reload. With the monorail, you'd still have to get people off of the train at 15-20+ feet up in the air, you have to then transport them, and as the system doesn't always follow areas where this (nor evacuation routes) can be easily accessible, it makes it further complicated.
And, then, even after you've gotten everyone off, a broken monorail tanks the line, and potentially backs up the entire system, but because there is no live operational track switching inherent to the system, with runoff and avoidance tracks, like a traditional railway would have to allow trains to "pass" each other, combined with the fact that Disney is already averse to using track switches when the trains are occupied as much as they can since the accident many years back...yeah, just not gonna happen.
And, even after you've done that, if you can't get the train rolling again, THEN you have to usher out one of the tugs. Refer back to how "easy" that is to do, when the main line is clogged or taken at some point by other monorails, and there is no such thing as mass switching yards, like you'll find with more traditional rail systems.
It's an efficiency argument, not a lack of imagination.
And then there's the real impact on the Guests. If you've ever seen people irritated waiting for a bus (where capacity can be rerouted quickly due to demand flux because of the quasi flexible routing system due to utilizing the road networks)...you'd know that waiting 35 minutes for a slightly higher capacity vehicle...won't fly well. They won't care for it. You can see it, the crowd sentiment, on a hot summer afternoon at TTC...or in the rushes at MK at close to get back to TTC to get to their cars.
It's a traffic choke point. Wonderful idea, really, I adore the monorails...but, they really aren't able to keep up with traffic demands...not without major overhauls, and that means a lot more than $20 mil a year, or even triple that a year...
If we do see any train development, the best I'd imagine is a streetcar system...but, I strongly doubt Disney will ever set up monorails as a traffic system (as opposed to a "peoplemover" partial attraction) ever again. It was an experiment when they expanded it to EPCOT, not to mention thinking it was a great idea to bottleneck all of the traffic inbound to MK with it (and the boats)...and it just...didn't work as well as hoped. Certainly not with today's attendance numbers.