Funnily enough, whenever virtualenv and virtualenvwrapper cause problems for exactly the reasons stated in the article I do give the internet a try.
Whenever I stumble across a new problem and google for it there is a huge wealth of information about what's causing it and what the workarounds are. That's great news for me, but not so great for your bullshit 99.99% figure. A rather large number of people have run into the same problems, a huge number if you assume that most of them don't post about it since someone already has.
Also funny is that there are now decades of experience with shell tools and programs, much more than there is with python, nevermind virtualenv. Perhaps they have best practices for a reason?