JUST MY VIEW:
Python probably didn't get popular when Guido released it. I was using it 10y ago and it already had a lot of libraries and "batteries included" then, but it was still far from mainstream.
I think it got mainstream after the RubyOnRails Wave that made a lot of (mainstream) programmers (that only use what other use and/or is popular) accept dynamic languages. And when BackSlash came (Ruby is Slow, RoR is full of Magic) python w/ django was the dynamic lang that clinged on shore. Not accidentaly since it already had pretty clean core and a lot of libraries (it always had more libs than ruby). Now everybody uses it.
If you look at the similar languages w/ a lot of libraries and bindings php/Perl/Ruby/Python it's not weird that it's popular and I would say that it is the simplest/cleanest.
Yes, Python was strong before Ruby (which I indicated hopefully), but it wasn't as mainstream as it is now when it's everywhere (at least in circles around me).
I back then used it for a lot of things and most weren't related to web. But I think it made the biggest jump after Ruby backslash. From quick peek at TIOBE:
""" "Programming Language of the Year" award winners is shown below. The award is given to the programming language that has the highest rise in ratings in a year. """
Mailman, the original BitTorrent client, Gentoo's Portage/emerge tools, yum, Eve Online, and a large swathe of 90s-era Red Hat Linux system configuration tools have all been written in Python, all predating Django and your "Ruby backlash" timescale by at least 2-3 years. And not one of them is web-related.
Most of the code that gets written in Python has nothing to do with web development. Web development is just high-profile.
Perhaps you are putting too much emphasis on the Python world's support for programming web apps. Python is also a good programming language for many of the jobs we used to use Perl for, but with much cleaner syntax in a lot of cases and with more batteries included. That is how many of us first discovered it.
I think it got mainstream after the RubyOnRails Wave that made a lot of (mainstream) programmers (that only use what other use and/or is popular) accept dynamic languages. And when BackSlash came (Ruby is Slow, RoR is full of Magic) python w/ django was the dynamic lang that clinged on shore. Not accidentaly since it already had pretty clean core and a lot of libraries (it always had more libs than ruby). Now everybody uses it.
If you look at the similar languages w/ a lot of libraries and bindings php/Perl/Ruby/Python it's not weird that it's popular and I would say that it is the simplest/cleanest.
Which ones did you mean as simpler?