Any strategy that shows success has to be considered legitimate. In this case the strategy seems to be two-fold. First to pick up those fish stacks (love that term), second, and equally important is to put other players on tilt, thus making bad decisions.
A quick story. I played a 30 seat SnG at Stars last year and watched one guy max the bet every hand. EVERY HAND. By the time he finally lost a hand he was such a big stack it barely dented him. He showed down garbage nearly every hand, and sucked out on most hands. I got lucky in that one as I hit nothing early, and saw what was happening. I folded EVERY HAND. I came in second in that SnG.
My guess is that it was a fluke, that his strategy is not profitable in the long run. But as I have not had the balls to explore that strategy, I can't be sure of that. Certainly if, for whatever reason, somebody starts off big and aggressive, they can amass a large enough stack to overcome a lot of beats.