Some players have yet to finish their 1st round match. Some finished their 2nd round. Doesn't seem fair. Couldn't they schedule a couple of more matches on CC under the roof today? Hopefully weather co-operates tomorrow otherwise they will be majorly messed up with no middle Sunday play rule.
It is what it is. Unlike the other surfaces, grass still is a living surface. It needs rest and cannot be overplayed or else the grass will wear away even faster than it already does. 3 matches per day is better, 4 is stretching it. It's risky playing any more than that. Center Court is played till the end of the tournament. A better long term solution for bad weather might be to put a roof or some imaginative engineered form of tent canopies over at least a couple of other courts, but if the bad weather is near the beginning of the tournament, even that won't help a great deal as there are just too many matches - 64 1st rd. matches in each singles division, not to mention doubles, mixed, juniors, etc.. The outer courts can handle 5 matches/day the first week.
Then there are also practical matters like making money, sponsors, tv commitments, etc.
The players that have played on center court all have future opponents that have also completed their 1st round matches. The players that have not played on center, such as Wawrinka/Del Potro, have future next round opponents that have not completed 1st round matches.
I believe they are being as fair as they can be given all the circumstances. Hopefully, there will be some dryer weather along the way so they can catch up.
Respectfully,
masterclass