The DR has a historical moral obligation to Venezuelans.
In colonial times, especially during the multiple and bloody Haitian invasions, it was Venezuela one of the predilect destinations of the Dominicans that simply had enough of the abuses. At one point 2/3rds of the Dominican population packed up and left the island, a large percentage of them headed to Caracas and Maracaibo. Even the Duarte family, and Juan Pablo Duarte himself, died in Venezuela and many descendants of the Duarte family live in Venezuela or are Venezuelans.
During the Trujillo dictatorship, Venezuela again welcomed those Dominicans that left due to having discords with dictator Trujillo.
During the Dominican economic crisis of the 1980's, that in 1984 exploded into a full force riot in Santo Domingo, Venezuela was again the land of milk and honey for thousands of Dominicans.
Many of the Dominican emigrants in colonial times and in modern times returned to the DR. Venezuela simply made it possible for them to conserve their lives and/or their family honor / human dignity before returning back home once conditions permitted them. Many Venezuelans that currently live in the DR and have no recent ties to the country, probably have a long forgotten tie to the DR, given the thousands of Dominicans that left for the Venezuelan shores during the past 200 years; especially those that are from Caracas or Maracaibo.
The DR owes big time to the Venezuelan people. I personally don't think the DR as a society can ever fully repay Venezuela for that, but gratitude needs to be shown. Never know if in the future the tables are turned once again.