Patrick is "not a race car driver," Petty said.
Instead, Petty said, Patrick is a "marketing machine" for NASCAR.
"Danica has been the perfect example of somebody who can qualify better than what she runs," Petty said.
"She can go fast, but she can't race. I think she's come a long way, but she's still not a race car driver. And I don't think she's ever going to be a race car driver."
Petty, son of NASCAR legend Richard Petty, said Patrick could have been a race car driver. But he said now it's too late for her to learn.
Patrick's fans have reacted to Petty's comments, saying that other rookies don't get the same kind of criticism, suggesting that she takes heat for being a woman.
Patrick finished No. 8 at the Daytona 500, just after she became the first woman to win the pole in a Sprint Cup race. Patrick has seven top-10 finishes in 60 career Nationwide Series races.
Petty said he did not know what skill distinguishes a good driver from a great driver, since he never became one himself.