I agree with BJJ - I wouldn't want to give up Minor scoring. I don't think Major scoring would be a positive influence on my shooting.
Also agree with VolGrad - the stress of competition is very real for many people. It certainly is for me. Private informal competition against buddies, or in training classes is good and it's something, not nothing. But it also doesn't hold a candle to the intensity of formal, public competition. Same thing but with a much more powerful stress effect for me.
The practical solution to that is probably the most important aspect of shooting: on demand performance.
I have to retreat into what I can reliably do with the sights and trigger. There isn't any bullshitting about what you can do in competition, which is one reason why plenty of people would rather talk about intangibles from behind a keyboard, than allow themselves to be judged in a public competition. Also because intangibles can be talked about from behind a keyboard anytime, whereas you can only go to an actual competition when one is going on and you can attend it.
And that's not unrelated to the relationship between competition, training, and field experience...which in an important way boils down to a simple question of availability.
Borrowed from Bill Rogers: Combat IS a competition.
Winning is a priority. I know, I know, we are discussing the 'how to get there' part.
I agree that experience matters, but obtaining real experience is also irrelevant to a lot of people. Those who don't have jobs that require they deal with hostile parties in ambiguous situations and make use of force decisions simply do not have the option of amassing real experience. Just the way it is. So when you are that person, you do what you can. That includes training, which absolutely should be guided by the bedrock of experience that comes from others who have BTDT, and whatever else that can be done to build skill, induce stress, and help model effective behavior. One of the most readily available and inexpensive opportunities nonprofessionals have to
shoot and gunhandle under stress is competition. Training too, but that costs a lot more and often focuses on different (and very important) aspects of the puzzle.
But I do think that the best stress competition has to offer comes from 'getting in the game' and trying to win. It may be a balancing act to try to win, but not do every possible thing you could to win (not sacrificing gear priorities is a prime example.) Honestly trying to win enables a lot of the value for me though.