Sounds like I'm in the minority, but I find I play better/concentrate more when I'm alone. When I play with others I tend to feel rushed, like they're waiting for me to play so they can hit or something. When I'm alone, I take more time to line up the shot and my practice swing(s) are more deliberate and with better tempo. It's my own fault for not taking ownership of my own game, but it's a big reason why I perfer to play alone.
I will say for myself also, that I'm not someone who will come out at 9am on a nice day and expect to be let on the course by myself, especially because I walk most of the time. I'm almost always first on the course, OR I will come later in the afternoon when it's slower, at least on the tee sheet. I may run up on some people, but unless I'm chasing the setting sun, I'll be walking and taking my time so as not to play behind people.
I am with you guys in that I am more focused when I'm alone. I'm not distracted by conversation, I take my time reading the greens, etc. I take golf more seriously than 90% of the people I play with so when I'm with others, I tend to take it a little less seriously as well.
Yes, this is basically a great idea. I used to play alone all the time. But I never would now, especialy if it was like a bacelor party or my birthday. The course I play at is pretty much dark or dusklike all the time, and it is very uncomortable because right behind the parking lot is a huge graveyard. I don't believe in that stuff, but one night when I was playing with myself I swear to you that I saw some type of phantasm or disembodied spirit.