I think the Philipino cruise ship crew popularity is cultural, in that it is both an admired pursuit for Dad (or Mom) to go off to sea, and send back some good money to support the family. Plus, they tend to be very personable and hospitable, making them valued service employees. Also, musical talent is fostered, and many of the musicians are Philipino.
Excellent analysis!
Did the Alaska cruise last year in early June ... later in late September we cruised the Aegean boarding our ship in Istanbul. Both ships had mostly crew members from the Phillipines and other southeast Asia countries. Very friendly and within a day or so many of them knew us by our first name. Also, when they had a 'crew' evening talent show to entertain the passengers many were quite talented musicians and singers.