It's important to remember that trade in the Philippines wasn't focused on the Philippines. It was focused on China, so the Spanish had no incentive to encourage any kind of economic development there. If anything it would have made their conflict with the Moros on the southern islands more difficult. The world economy had changed enough by the time of the US colonization that you do get some forms of plantation development and a more serious interest in political administration of the Philippines, but whereas the Spanish mostly neglected the country, the US was highly extractive.