I replaced front brakes and rotors about 5000 miles ago. The rotors are already all full of grooves. The pads are good. The rotors were extremely cheap about $20.00 each. The brake pads were not cheap, they are supposed to be very quit which they are but extremely dirty as the wheels will be black within a couple hundred miles.
I don't understand why the rotors would be all full of grooves.

Lots of brake dust and grooves in your rotors tell me you probably bought ceramic pads. That was a good decision, but you should have bought a more premium rotor.
At $20 each you got what you paid for.

Thats exactly it you paid 20 bucks for em and you got what you paid for..Sorry not trying to be crude if i sound it i aplogize