I am not talking about line maintenance. Neither am I talking about based aircraft with a fleet of replacement aircraft on hand. I'm talking about casualty aircraft that may only fly in a one or two times per day from thousands of miles away not a 737 hopping across the channel.
I think I've seen one engine change at MAN outside. The rest were all in either the BA or FLS/TC hangar. With good reason. If you are involved in aircraft maintenance you will know why.
Why you want to belittle the job by suggesting its just to keep the engineers dry during a wheel change beats me.
High winds, freezing temperatures, heavy rain can cause real problems.
World class airlines want world class facilities at their chosen destinations. There is no reason why maintenance should be any different. If you think its expensive, try having an accident.