Due to numerous inquiries GMA FEEDBACK has received regarding the use of Filipino as the language in some of the animes, GMA is issuing the following response. There are reasons why GMA has to dub some of the animes in Filipino and while GMA wish that they could give in to all of your demands, there are certain limitations as to what we could do.
Original Title: Why are some of your Favorite Animes Dubbed in Filipino?
Original Source: GMANetwork.com | Kids – Anime Update (Web Archive)
Original Published Date: January 4, 2000

GMA understands your request and desire to have the anime shows aired in English. GMA also prefer to maintain the originality of the anime’s English version. In fact, it would spare them the Tagalog dubbing expense if they showed your favorite programs in English.
However, the decision to air in Tagalog or English is not GMA alone to make. The truth of the matter is that the Japanese license owners of the anime programs dictate to us what language they want the show dubbed in.

Because of new distribution technologies thru satellites, most anime companies insists GMA to dub in Tagalog. This will give them assurance that the network cannot re-sell the show to any other country but the Philippines only. Furthermore, even if other countries are able to pick up our signal via satellite, the Japanese owners of the anime can still sell the anime to that country because it was aired in Tagalog. If it were in English, then they would have lost that market all-together.
So GMA hopes you understand that dubbing in Tagalog is not their way of destroying the anime. More often than not, it is on the insistence of the Japanese companies to protect their worldwide intellectual property rights from being infringed upon.
There are however, exceptions to the rule like Pokemon, where the Japanese owners insists to air the English version.
Secondly, though we have a lot of people wanting us to air in English, GMA even have more kids audience that want the network to air in Tagalog. 80% of the audience comes from the DE class. These are kids whose parents earn less than 5,000 pesos a month. They don’t know a word of English, yet love anime. They don’t have access to e-mail so they can’t tell us their side. But based on their research, for every 1 person who wants it in English, there are 8 anime fans who want it in Tagalog.
These kids have no other way of watching anime except via GMA. YOU probably do. Since most people have access to internet, they probably are fortunate enough to have cable, or money to buy the English videos. The kids in the DE category who can’t even go to school have only 1 option, GMA, and so it is important to them to think about them too, or in fact think about them first. And these kids want it in Tagalog.
What is important to the network is that GMA brings you some of the best anime shows the world has to offer. No other network does this, only GMA. “We trust you understand our position”.