I have 12 bps now, and at least half of them have bitten me at one point, and two of them kept it up for a good 6 months or more. I think a lot of new hatchlings bite because they're hungry, and they don't know better; and some of them keep biting even as they get older because they're more fearful; and some yearlings and juveniles continue to bite because they're just plain old ornery. But all of mine have grown out of it, including Mr. Nibbles and Miss Pissy Pewter. I think 98% of them grow out of it, just because it's not the way adult ball pythons operate.
And I think weekly handling does help, especially when they're young. I think it helps them accept humans as part of their environment, so they don't stress too much. And that's what really makes them "tame". A wild-caught adult can be sweet as pumpkin pie, but still be too stressed to eat.
(I don't necessarily believe in domesticated ball pythons, but I do believe in tame ones. But I think we're splitting hairs on the definition of the word, and the real answer is: yes. Some of them take a year about it. But she'll chill out eventually.)