It wasn't really all that much fun.
At least not if you used an actual Wiffle Ball (registered trademark).
Sure the holes in the white plastic ball allowed it to simulate curveballs. Or so it said on the box.
But that design also kept it from traveling far or fast. Playing backyard baseball with an actual Wiffle Ball was like being in the dead ball era.
No, what you wanted was a plastic ball that was solid on the outside. Pitchers could get plenty of heat on their fastballs and still achieve remarkable movement. And hitters could smack line-drives and long home runs -- not just wounded ducks fluttering back to the pitcher.
Reasonable people can disagree about this.
But it says here that playing wiffle ball with a Wiffle Ball was a slow-motion drag.