To pick one of your charged examples and put a face to it, wouldn't you say Alan Turing might have decided to stick around if he knew he would still be young and healthy in 2010 and society would be accepting of homosexuality?

Eh. Turing committed suicide after two years of chemical castration by hormone injections (which can significantly impact personality and cognitive functioning), I'm not sure he would have been willing to put up with 11 more years.

It's also not clear to me that LGBT rights would have advanced as quickly in the UK without Turing as a martyr, and so he might not have been looking at only 11 more years.