The infield-fly rule exists for the simple purpose of discouraging infielders from deliberately dropping pop flies in order to double up base runners on force plays. That’s of course why the rule comes into play only when there are fewer than two outs and runners on first and second (or first, second, and third).
If the infield-fly rule were repealed, infield pop-ups would regularly become momentous plays: Will the infielder fake out the runners by dropping the ball, or perhaps instead by making them think he’s going to let it drop and then catching it at the last moment? I don’t understand how any baseball fan would want to dramatically increase the prospect that games would turn on such silliness.
I’m amenable to the suggestion by William Juliano that the infield-fly rule be amended so that the “defense should be limited to recording one force out” when the infield-fly rule is called. (In other words, if the fielder drops the ball, deliberately or otherwise, the defense could get only one force out.) I’ll note that Juliano’s suggestion cuts in the opposite direction of Rick Klein’s: Under Juliano’s, the defense would get zero outs or one out on a dropped pop up, while Klein wants the defense to be able to get two outs (and presumably even three).