Because they can, that's why. You have to understand that in the US, we cater to the telecommunications industry, they don't cater towards us. Everything is designed for maximum profit, and customer interests/satisfaction are less of a concern.

Compared to a place like India, the US's cellular market is strange and backwards.

No wonder we (and Canada) have the highest costs for mobile phone service in the world.

EDIT: http://arstechnica.com/gadgets/news/...l-packages.ars (just wanted to back up my claims)