You need some perspective and change expectations. He made the semi's with such a tough draw. He clearly was not 100% for the Murray match. He came out wearing his vest. He has been having back problems but he doesn't complain and make a big deal of it.
He still took Murray to 5 sets when he looked like he didn't have much left in the tank at the age of 31.
Given the right draw and conditions he is going to win one or two more grand slams.
'Its nice to be important but its important to be nice' - Roger Federer