In general I agree with this sentiment, but Anaconda is different. It’s easy to install and a lot of people install it because they’re told it’s “Python, but better” or because it sounds like a neat idea or even just for kicks, without having a clue what it’s doing to their system. It’s got to the point where I have at least one person using Anaconda in every tutorial I run, and they almost never understand why it is making rospy usage fail. Having not used it myself the first couple of times this happened took me a while to fix, but now it’s got to the point where when someone is having trouble importing rospy the first thing I do is open up their .bashrc file and look for references to Anaconda. I don’t ask them first anymore, either, because a couple of people didn’t even remember installing it.
Having a good question and answer on answers.ros.org is a good idea, but I think there is benefit in putting a very brief note with a link to it on the rospy tutorial page or somewhere like that.