Because disabling or changing the cloud settings can give you huge advantages over people or AI in aircraft and as a Anti-aircraft unit, the server or mission should be able to force cloud settings like they can force view distance.
This is a huge issue because people will use this to cheat in PvP, Coop and singleplayer missions.
Make the same also for grass!
People shouldn't be able to disable it dipending by server configuration.
The big problem with disabling clouds is aircraft and Anti aircraft are heavily affected. Any hope a player had of using clouds to conceal his or her aircraft or paradrop is lost when someone disables clouds to cheat.
The point of clouds concealing aircrafts is a bit mute really. the clouds are so high that choppers will always fly under it and jest if they want use clouds as cover has to go to 2km (or something), way out of range of bullets. The only thing that will hit the jet is an AA launcher or other auto-targeting lock system that can deal with jets. The lock will go right through the clouds so nada concealment.
And from the chopper perspective... I really want to see a slider in the weather settings of the editor where you can set the cloud altitude. Default hight is realistic, but you really can use lower clouds in a lot of missions.
The clouds does not really use that much resources (compared to grass for example), so either way is fine for me. I can imagine that players with old pc´s want to get every frame they can gain.
The slider is here: http://feedback.arma3.com/view.php?id=8492 But this isn't just a vanilla problem, mods will have this along with anything else that flys or falls from the sky.
A person using AA will disable clouds to spot players or AI that are hiding up in the clouds.