Many Filipinas find Western men attractive, and so do many other SE Asian ladies.
While the assumed economic might and resulting confidence play a role, a lot of the attraction criteria they have seem to be built into their DNA and the subconscious.
Our human instinct is to improve our species, so that our children have a better life and better standing in society. To many a SE Asian, it first and foremost means the children's physical appearance.
My theory, again, is that it harks back not even to the Western colonial times, but to the Greater India times. The Indian Raja rulers of SE Asia were Caucasian looking, with thin noses and an elevated nose bridge. The toiling masses were darker with no nose bridge and broad, flatter noses.
Thus, for hundreds or even thousands of years, the upper caste's physical traits would be seen as very desirable by the commoners all over Indo China and the islands near it. Having children with one would elevate the status of the offsprings and propel them to a higher caste. This standard became imprinted on the subconscious and passed through the DNA programming to all the future females in that part of the world.
European and later American colonial males got to benefit from it by being seen as desired carriers of such social- improvement genes. Note that, unlike in the European/American obsession with blond hair and blue eyes, those two do not matter to SE Asians.
But what about if the man is not handsome?
He still has lighter skin and an elevated nose bridge- and can still make children that would be handsome.
But what if he is older, overweight, bald and short?
Does not matter, as he still has those two vital characteristics which can be passed on to the future generations. He is still a gene-holding entity which will create benefit for the family pool to come.