This teacher finds this too.
I would question the comment that playing quietly requires more control. I think playing very loudly requires just as much and I find very few players who can do it well.
I must say that playing regularly with a band is as useful as practicing at home, in this concern.
Some great musicians allegedly used a softer reed at home to increase control and a harder reed when playing live.
The most annoying aspect of people not used to play loud, is that they tend to go horribly flat when they do. This is one of the reasons I take ages to select an instrument or a mouthpiece: if it sounds great at home, it does not mean it will sound great on stage.
Playing outside, with no reflecting surfaces, is quite an experience. You need to trust your own sound.
A friend of mine used to go and practice on the pier, to improve his sound. I am not aware of any ship accident that could have been his fault.