Why Dr. Mahathir insisted on using English for math and science?

This is because the whole world uses the language as an information and/or technology language. How dangerous it will be if we try to use Bahasa, especially in school. See example below.

hardware = barangkeras
software = baranglembut
joystick = batang gembira
plug and play = cucuk dan main
port = lubang
server = pelayan
client = pelanggan

Try to translate this:

ENGLISH : That server gives a plug and play service to the clients using either hardware or software joystick. The joystick goes into the port of the client

Now in BAHASA: Pelayan itu memberi pelanggannya layanan cucuk dan main dengan menggunakan batang gembira jenis keras atau lembut. Batang gembira itu dimasukkan ke dalam lubang pelanggan.