It's probably pertinent to mention that the Python installation ecosystem is a hot mess, with multiple ways of installing Python (e.g. standard Python installer, multiple different packages managers on different OSes, Conda, and myriad package managers which can also install Python. And of course, these can all be in different locations, and may have different approaches to installing libraries.
Which is to say, I don't blame the author for wanting a single installation that his app can manage and rely on, even though I wish it was different.