Really? Who?
As a poster that was bullish on JKO long after it was more popular to bash him, I don't think I ever saw or read anyone arguing what you suggest...
I was wrong about JKO figuring it out by now, and it looks unlikely he'll put it all together (though, not impossible)... But Zadina is literally out of the NHL with a career best year of 24pts, despite playing on two bottom feeder teams desperate for scoring.
Habs had a brutal development program in place when JKO was drafted. Was the RedWings development program as bad? I'm not so sure, but either way, Zadina, like JKO, certainly didn't suffer from not getting a shot.