I've been aware of this geographical disparity but realized I have no idea why it is so. It doesn't seem to be like the difference between a hero, a grinder, and a hoagie. If I'm understanding it correctly, ziti is essentially smooth penne with flat cut ends. Are there other differences............ I mean beside the fact that your grandmother made baked ZITI, not baked smooth penne?
Mostly, I'd like to know HOW something so much a part of family dining in the East could have totally disappeared West of the whatever divide. I've never seen Ziti in the pasta aisle at any major market in SoCal............... though I'm sure I'd probably find it a someplace like Claro's Italian market.