It's no different than Doberman ears, which are typically cropped. It's just one of a variety of ways pit owners/breeders like to see the ears in their dogs. I prefer pits with their natural floppy ears, but to each their own.
They are definitely cropped... you can see the unnatural pink outer rim of the ears. There's not nearly enough hair there... cropped ears in pits is extremely common. Most people don't even do it right... but it my opinion it shouldn't be done at all. Not many people do it in a nice way.
I agree with you. I had a pitbull bitch and she (Molly) had nothing changed. I love Pitbulls, they have really good temperaments and are just the right size. I have a heinz dog, and I love him, but he does not have the brains of a pit.