It seems not many are interested in this question, so I will try to provide my own experience as an answer.
I think isolation itself is not a drive for productivity, but it creates the good conditions:
It eliminate the noise and interruption, which is very bad. Many studies point out that the time we spend for re-concentrating after interruption is a lot.
It's a change of environment. In my experience, any change of environment makes me feel more alert and conscious (for example, change of work, going to a new place...). The environment change makes the brain work and disposes the old "comfort zone", which create a place for new ideas & thoughts.
I have spent several months studying mathematics in high school. That's when I took advantage of an abandoned house of my aunt's when she was preparing her new house. The only thing that made me stop at that time is a meal, which I took alone too.
Strangely, in such an empty room with a few books, I felt much more concentrated, and got hundreds of problems done within days. I didn't think much about what happens outside, just math, math & math. The result surprised even me.
But that's only my experience, and the experience may change with personalities. I know quite a few people who will be crazy if they were in my case. But somehow being alone doesn't bother me that much.