Two things make Barbados unusually practical for a destination wedding. The first is the paperwork: the island is well known for a straightforward licensing process for visiting couples, without the extended residency requirements some neighbouring islands impose. The second is the geography — because Barbados is coral rather than volcanic, it has no mountain roads, and moving guests between a ceremony, a reception and a hotel is measured in minutes rather than hours.
It is also the easternmost island in the chain, which puts it slightly outside the track many Atlantic storms follow through the Caribbean. That is a tendency rather than a guarantee, but it is a real factor when comparing dates against islands further west.