I would generally not see the need, except I spent an hour helping a friend set up a Python dev environment, and it was terrible. The problem wasn't that the env itself was hard to set up, the problem was that it was very hard to figure out which Python it would use, where the packages would go, how to prevent the other four Python versions installed from interfering with it, etc.

This looks pretty great, so I'm probably going to give it a shot. Then again, a script would use a specific/known Python version and create a virtualenv with would also work.

EDIT: Maybe I should write a script that downloads all the necessary files somewhere and creates a virtualenv with a given Python version, a la `curl https://www.whatever.com/setupvenv.py | bash`.