Football is inherently unfair though, isn't it? Its not a level playing ground and never has been.
There's nothing really fair about a league where some clubs have squads worth £100m and some worth £800m. Is it fair that the transfer window means you can play a much stronger version of a club in February than your rival played in December? Is it fair that some clubs had 3 weeks between seasons and some had 8 weeks? Is it fair that you can have 2 or 3 days less rest than your opponent from week to week? Or that in April one title contender might have a derby sandwiched between 2 Champions League games while another has a guaranteed 3 points vs a relegation candidate?
It is unfair to have some clubs with fans and others without, but it's just one more on the pile of a pretty unfair sport.
The postponed Aston Villa game might get played in front of fans which is unfair on Villa. United will have to play the other derby at a full Etihad. We'll play Spurs in front of fans while they had none. So I think from a City point of view we are doing reasonably well.