The Heat nearly did sweep everyone last year. If Lebron wasn't a headcase; they probably would have.
The Rockets won because of their bigs, the Spurs because of their bigs, the later Pistons because of their defense with some help from the imploding Lakers. The Heat won because of Wade+Refs. Rondo certainly helped the '08 Celtics, but he certainly wasn't their first or second most important player. The Mavs won because Dirk was playing out of his mind, then other people stepped up around him, including Kidd.
My point: Defense, rebounding, and low post play almost always determines the winner in the playoffs. In fact, I'd go as far as to say; traditional PG play becomes LESS important in the playoffs.
I love watching good PG play. It's way more fun to watch than ISO basketball. The players you listed above with the exception of Isiah Thomas, did not cause their teams to win the finals, players like Hakeem, Dirk, Wade, and Duncan did.