What are some pragmatic reasons for preserving the diversity of Philippine languages?

Dr. Dacudao of SOLFED, Inc. cites two practical reasons for preserving the diversity of Philippine languages <http://tinyurl.com/35uzpo>:

1. Some languages which are difficult to learn can form the basis for military codes. See, for example, the use of Navajo during the Second World War <http://en.wikipedia.org/wiki/Code_talker>
2. Some languages which are easy to learn can form the basis of a trade or scientific language, e.g. Latin.