The USVI charter business is certainly not dead - the transition to the BVI goes way back to the 1980's and was influenced by a few factors starting with the changes in the IRS passive/active investment deductions. The lack of large affordable dock space for fleet operations is still affecting the industry in the USVI, the improvements over time particularly in the provisioning and repair capabilities, in the BVI, also made the change from STT harbor based charters moving to the BVI attractive, the rapid emergence of large BVI bareboat fleets was also a tax based decision and the perceived 'more time in the BVI' did push that movement along as things got so much easier to bareboat there. The huge shift from crewed to bareboat charters with fleets of identical vessels vs. the distinctive yachts that serviced the industry in the 70's and 80's really made a difference and changed the demographics of charterers in favor of the BVI with its growing bareboat companies.
I really miss those old elegant charter boats on the docks in STT Yacht Haven as a personal aside.
When STT in its heyday was the charter capital of the Virgins and only competed with Antigua - the crew services, booking offices, chandleries and provisioning were all far ahead of the options available elsewhere.
And of course the air traffic landing in STT made it a very desirable destination, the problems of BVI access are still discussed here daily.