Because I average charging $2,000 or more per month and they make about 3% on that from merchants fees.
I get 2,000 or so points every month accumulated.
they make maybe 1%, there are a lot of middlemen in a credit card transaction.
1% of $2,000 is $20. It costs more than that to have you as a customer. Even if their profit is 3%, thats only $60. Add in those points and you are costing them money.
Again why would they want you as a customer?