I never said anything about Wimbledon. You are trying to deflect from your fallacious assumption that it was all preplanned and Fed did not enter RG with the intention of going as far as his body will allow.
It is his body. He has the right to decide when to push it and when to pull back.
A player may not go after a ball that is difficult to get in an ordinary point. But, if it were the match point, they might do it. You cannot accuse the player of not putting faithful effort for the former case.
Finally, I think Fed has now played 1513 matches. As far as I can recall, he gave walkover in three matches. This is one, a walkover to Novak at ATP finals after a gruelling match with Stan and a walkover to Blake in a minor ATP tourney. Similarly his retirement during a match is almost non-existent. I would let you find similar figures for other members of Big 3/4 and post them (before I do).
You people are making a mountain out of a molehill. As I said before, if Fed has entered into Stuttgart (which was being held during second week of RG) and got out of RG (despite still being in it) in the middle just to play on grass, that would be disrespectful to RG. Not if he quits in the middle to protect his body from anticipated damage if he continues. In case you are not aware, lot of lower ranked players routinely enter into a GS and at the same time also into a tourney that starts during the second week of that GS (as they don't expect to make it to second week of GS).