But if you rebuild python from scratch, you loose every single software packaged by your distribution. If you depend on modules with C extensions, it quickly be

But if you rebuild python from scratch, you loose every single software packaged by your distribution. If you depend on modules with C extensions, it quickly becomes intractable. Building python is easy - building a recent pyqt on RHEL 5, not so much. Also, virtualenv is hard to sell for people who do not know so much about python.