The Infield Fly Rule is obviously not a core principle of baseball. Unlike the diamond itself or the concepts of "out" and "safe," the Infield Fly Rule is not necessary to the game. Without the Infield Fly Rule, baseball does not degenerate into bladderball the way the collective bargaining process degenerates into economic warfare when good faith is absent. It is a technical rule, a legislative response to actions that were previously permissible, though contrary to the spirit of the sport.Here's a discussion of the article at Topography of Ignorance.
(Tip of the Mariners cap to ronb78 who pasted the link at Lookout Landing.)