Learn? Nothing. Perhaps, I don’t know, remember how to see pitches and stop guessing? Fix a swing that was wildly falling apart?

“And how could Hardy possibly be less valuable than Iribarren?”

A) Escobar is Hardy’s chief replacement and any drop off from Hardy to Escobar, given the team’s falling off of a cliff, is negligible.
B) Hernan is the 25th man on the roster. If you think having Hardy be the 25th man instead of Hernan is in any way a scale tipper on a team not in contention, well, there’s nothing else I can say. An average player who doesn’t play is just as (un)valuable as a replacement-level player who doesn’t play.
C) Hardy was still on pace to post less than half the WAR he posted last year. What you and Mr Cameron and Mr Golebiewski and the like are missing is the Brewers aren’t counting on and aren’t planning for JJ Hardy to be a 2 win player. He was worth 4.5 wins in 07, 4.9 wins in 08 and a screaming 1.4 this season. Even though he’s still a league average player that doesn’t mean he’s not broken! That doesn’t mean he’s flawed and that doesn’t excuse an awful year. We should just pat on the back straight A students who suddenly become Charlie Brown because straight C’s is still “average”? “Hi, Dad, I know I’ve received straight A’s all the way through high school until this year where I’ve been getting C’s but don’t you worry I’M STILL AVERAGE! And you better not ground me because that would constitute abuse! And Dave Cameron would be on my side!”

…I really hate posting this flat panel TV analogy again, but:

‘The argument that he shouldn’t be sent down because he’s still better than most of the other players at his position is absurd. Say I have a 70? flat panel television in my living room. The colors are great, the black levels are deep, and the native resolution is 1920×1080. It’s just an awesome set. But one day, it stops displaying images in HD: 480p is the highest resolution the set will display. I’m still getting the colors and the black levels, but the clarity is significantly reduced. But, hey, I still have one of the five or six best television sets on my block, why should I bother calling a repair man?’

Hardy still being league average doesn’t change the fact that he’s miles from where he should be and that his absence from the team is nothing but negligible.

“One of two things is the case: 1) service-time games are being played or 2) the Brewers are dizzyingly stupid. Take your pick.”

You are part right that there is some “dizzyingly” stupidity going on. It is unfortunate, however, that the only alarming and reckless stupidity is coming from you and those of your fellow persuasion.