Why should divorce be not legallized in the Philippines?

The Philippines is historically a strongly Christian nation, with over 85% of the current population being Roman Catholics - a group known to be quite adverse to the idea of divorce. Like many countries with such religion, divorce is frowned upon, although (unlike most of those, and similar to most Asian countries) the country has preserved many fairly conservative laws and traditions, including the illegality of divorce. However, it has given some leeway in the cases of Muslims and foreigners.

Basically because it is a catholic country which hasn't yet uncoupled church and state to the extent most other countries have.