This is a tough question to answer.
And that is probably why there have been not a single answer for almost 2 years now since you first posted it.
Anyway, I used to live in the Philippines and have visited a handful of islands (PI has 7,100+ islands). I was based primarily in the Capital city but have travelled to about 6-7 of its regions (PI is made up of over 13 regions). I have visited hundreds of cities, municipalities, barangays, towns, provinces there but PI is made made of tens of thousands of those.
What I am saying, it is hard to put an exact definition to or an exact reasont to visit the Philippines as each island, each region, each province is essentially like a different county by its own. Each having a different language, a different topography, different beliefs, different way of life, etc. etc. etc.
Although even having said all these, I still say as a former local, what I still think that makes the Philippines amazing, is still it's best export--it's people.
Most still have that old country smile, that innocence and the hospitality that has made its people famous. They are a hard hard to put a finger on, they have theiir openness and their shyness at the same time, their spontaneity and their reservedness. And I just like their laidback way of life.
And the tropical weather, the tropical food and the foreign exchange rate. What can I say, a retiree's paradise indeed.