The more stations you have the more overhead you have, but not necessarily more passengers. Passengers aren't attracted by stations, they're attracted by fast, comfortable and convenient service.
The TGV and Shinkansen attract a high passenger custom and profitable operation because the speed makes them practical for long distance travel that would otherwise require airlines.
Yes, the system would be expensive to build, and it would be an official boondoggle because the overwhelming majority of the revenues would come from the increased tax revenues from the businesses that build up in the areas around the stations (which the train gets no credit for, of course). But the corridor along the Florida coast could easily support a heavy high speed presence.
If we just clean up the FEC tracks a little and run low speed intercity trains in the slots between freight trains, it'll end up a money losing heritage line, like Amtrack. No one will have the time to wait for the few daily trains to make their way along the track.
Personally, I also support a private company building it. Forget tax dollars. This can be very profitable, so people who know how to run a business should be in charge of it.
Claude