Lennox Lewis didn't have a bad chin. He went down twice in 44 pro fights. Everyone got dropped more times than he did - except Vitali and McCall. Lewis had one of the best chins of any heavyweight in his era.
Lewis fought the biggest punchers of his era ... he went down twice. And in one of those knockdowns, he was up by the count of six (against McCall). That's it. Facts are facts. Holyfield was on the floor in his third fight with Bowe as many times as Lewis was his entire career.
Holyfield also got hit a lot more than Lewis did. Steward came in to polish up Lennox's defense. Step 1 was protecting that chin. Now, Lennox didn't have a bad chin. It was fairly decent. But definitely not china. Wlad has a far worse chin. So did Moorer. And maybe Haye.