Go to Queens in New York or the El in Chicago and see what an elevated railway is like. It darkens the street and gives a distinctly dystopia feel of the neighborhood. It’s why all El lines in Manhattan were eliminated.
Besides, there’s the cost of building miles and miles of elevated track. What would be the cost per mile?
The TEB solved some of these problems. Building a TEB track is way cheaper than building an El. Apparently, it can turn, but traffic must stop and wait. And height restrictions are quite common. Many Brooklyn and Queens streets with Els have height restrictions on them.
This doesn’t mean this wasn’t some sort of scam. However, you don’t build a working mockup with a scam. You do nothing more expensive than a four colored brochure.
I don’t think the intesntion was to scam. It sounds more likely that this was over promised and way more expensive than the backers realized.