because he, like 95% of the jazz's players, is wildly inconsistent.
I wouldn't even think of classifying Millsap in the same category as other inconsistent Jazz players. The guy is a tweener. His outperfomance-underporformance swings have everything to do with match-up demographics and little to do with Millsap's actual play. He's not going to be a beast against the Lakers. Miami is undersized inside. Millsap can find an edge in those situations. He really only found an edge, a fluke edge, for 5 minutes against Miami. The game wasn't stellar domination from start to finish of anything besides a 5 minute overtime period.
Y'all are fickle. Get off Millsap's jock ya bunch of armchair quarterbacks.