The same reason cold calling doesn't work anymore.
The amount of insurance company calls I get since I have to renew my car insure is absurd. They can go fuck themselves and I will never give them a dime.
"John" with a thick Indian accent on the phone isn't someone I would trust honestly. It's not a racism thing, it's the I don't want to give any information about myself to someone in another country especially when they specialize in scamming people.