Like I have alluded to, whatever you think of the Met’s output or whether the Airfield Operator is being overly zealous with the restrictions during forecasted rotors it is irrelevant. Ultimately, if you are not happy with the situation and want to own the risk yourselves, get your own airfield!
CBTL - Mount Pleasant Airfield does not belong to the RAF. It was built, at UK taxpayer expense, to allow for defence of the islands from a belligerent and bullying neighbour, but also to act as the International airport for the Falklands, to allow it to develop economically.
The question remains why the Operator is assessing the risk in a way that seems to be unique, when it appears that there are airports with similar or worse wind/turbulence issues that are not closed in the same way.
Your solution of building another airport would lead to one already under-utilised expensive asset being supplemented by an even more under-utilised one!