I find that as i live and work with the other half walking solo is like therapy for me, peace, quiet, fresh air, exercise blah blah.
I suppose i am a bit of a loner and enjoy my own company, i can walk at my own speed, eat when i want, pitch when and where i want and go to sleep and wake up when i want.
I love wild camping and going solo means less chance of being spotted, and if the weather is crap then i only have to argue with my self about making my way back to the car.
As to danger there is an element to it, getting lost by yourself or worse being injured, but common sense should prevail, and to be honest unless you have lost your map and compass and sense of direction you should be able to crawl to safety in almost any part of this country, and if you cant (ie on a steep ridge) you should really ask yourself 'should i have really come up here on my own?'
And if you get trapped by rocks, you could always do what that climber in canada (i think) done, After waiting a few days for rescue after getting his hand trapped by rocks he pulled out his trusty swish army knife and cut the hand off at the wrist, tied up the loose bits and walked off the mountain.