People use Python because the language gets out of the way fairly quickly to let you get things done fairly quickly. Sure, it isn't a rigorous engineering language, but the ratio of small projects that just need something good enough and easy to work with to large/complex projects requiring careful engineering is staggeringly large. While Python is definitely cooling off; people have been working with it for long enough to want something better - unfortunately there just isn't anything on the radar that is significantly enough better to overcome Python's third party library momentum at the moment.
Believe me, I'd love a language with a really flexible/optional functional type system, better metaprogramming facilities, a better concurrency design, slightly more consistent syntax, etc - just as long as it is still easy to think in and convenient to use like Python.