Ver complains that the decision has forced him to miss speaking appointments at conferences and that the US embassy in Barbados refused to even consider the evidence for his application.
The official reasoning behind Ver's rejection is that he doesn't have sufficient "ties" to his country of residency in the Caribbean and has not demonstrated he has "the ties that will compel [him] to return to your home country after your travel to the United States," according to a picture he tweeted of a letter that appears to be from the embassy.
In short, US officials are worried that Ver might choose to stay in his native country illegally.
This should be done to EVERY person who renounces their citizenship to avoid taxes.