platinum sprk plugs

Why did Mitsubishi go back in time instead of staying with modern technology by not putting platinum spark plugs in their new cars?
Does any one know where to get platinum plugs for a 2003 Montero Sport 3.0 V6?

I can get any NGK plug you want. I'm not familiar with the montero 3.0 but if you give me the NGK number (doesn't need to be a plat #) i can cross reference them and order them up.