that's true...
but to me, not giving your all makes a bigger mockery of the sport than chalking it up as a joke and playing the game differently.
Of course they would be better off scrimmaging themselves...but that's not what the schedule had for the day. Play, and play hard always.
Chalking it up as a joke would be having them clown around to waste time. Running different or more difficult sets or challenging them to dribble or shoot left handed isn't showing up an opponent. It's turning it into a challenging situation for your own team so they can get some actual learning value from playing, while not embarrassing your opponent. and giving them a chance to actually learn something too.
Like I said before, I coached youth football and have been on both sides of this equation. In one game, we were by far the better team. On the first play I handed it off to my best kid, and he walked, untouched, through the entire defense who never even got close to tackling him. Our first series on defense, they barely gained 5 yards and we got the ball back. Our second play on offense, we handed it to our second best kid, and he marched untouched for a TD as well.
At that point, I knew we were going to win the game easily. Should I have continued to hand off to my best two kids and watch them waltz through an over-matched defense? Would it really teach them anything? Would they really think to themselves, "If I ran harder, maybe I could score that quicker"? Or would they be much more likely to think, "That was too easy, maybe I should showboat a little more?" or "All I have to do is run in a straight line against every team and I'll score no problem". Should I just continue to run up the score with my best two players under the guise of, "Well they need to practice this for next week and I'm just teaching the other team how to take a beatdown, they'll be stronger for it"?
Instead, what I did was start putting my worst kids in at runningback and let them attempt some runs. I had my quarterback start throwing some difficult passes to try and get him used to opening up the run game. On defense, I took my faster pass rushers out and put them out on the corners. It forced them to cover more ground when trying to chase down runners, instead of being in their lap as soon as they got the ball. I had everyone play a deeper zone so they could get more used to seeing the play develop in front of them, rather than have the play be dead before it started.
I didn't ask them to play softer, I asked them to play out of their comfort zone. I think we only scored one more touchdown the whole game, and even gave up a touchdown. As a result, our QB got some in-game experience reading coverages, our receivers got a chance to catch some balls. Our worst players got to get some run for the first time all season and some valuable experience as well. On defense, my guys learned to take better angles and get in front of a guy in the open field to make a cleaner tackle.
All of that was valuable experience for my guys to learn, and helped down the road in other games. None of it was "showing up" the other team. The coach actually came up and thanked me for not being a douche and running up the score like a few of the teams before us. His team still lost by 14, but at least they enjoyed a game for once. My guys enjoyed winning, but also got to challenge themselves a bit.