Not necessarily, those who wanted to go directly to PC already got a direct flight from another airline. Those Arajet could have if they flew to PC.So, only about 10% of their passengers go on to PC? If they move to PC, they'll lose 90% of their revenue.
I don’t think tourists with a 1-2 week holiday in PC would enjoy an extra bus trip when they can go directly.
From Europa many Dominicans do fly to PC but mainly because there are few direct flights to SDQ and these are more expensive.