Who knows, maybe they prefer to pay lease charges on the 737s, rather than paying money to buy.
And if operational needs change, they can always hand the aircrafts back to the owners, rather than trying to sell them off.
Easier also if Bain decide, as some on here speculate, down the track, that they might find it easier to shut down.
And maybe the 737s lease fees are less than cost of buying, with lease payments being more economical than the cost of depreciation.
Leasing also means that VA2 does not bear the cost of ownership of aircrafts, ie, they pay an agreed lease fee, so no/not much maintenance charges.
I can see why they have downgraded that little bit, ie, to go all 737s, though of course we did love the 330 they had, and the 777s.
Overall, its all to do with what the new owner wants.
Probably not what PS/JB had in mind.
Mid range, buzz word for lower costings overall.
Compared to VA1, its all lean runnings now.