I can argue the opposite.
Have 4-player multi with Power Shots ON, then get a long rally going and watch your opponents HOPES AND DREAMS GET SHATTERED when you're able to return what seemed to be the winning shot, thanks to the recovery power shot. Then everyone gets tempted to use their power shots consecutively. Easily, you can end up with 5min+ rallies.
Sure, power shots can extend the life of the rally (more fun with shouting obsceneties at each other). But, that makes your regular tennis much more important. Conserve your power shots, play such a good tennis game using only normal skill that it tempts/forces your opponents to waste their power shots, then finally take advantage of their vulnerability with your power shot (to show off, of course). They'll hate you.