The Python Webkit DOM Bindings Project made python a full peer of javascript when it came to accessing and manipulating Webkit including HTML5 features. In essence, it could completely replace Javascript to help one build faster, more capable web applications using Python and HTML5.
With the limitations (and also the contempt that many programmers, including me, have for javascript) one would have thought that we would have seen a mushrooming of apps built with Python-Webkit. Rather the project seems dead now.
What went wrong with it?
(Python Webkit DOM Bindings - https://www.gnu.org/software/pythonwebkit/ ).
Same thing for backend developers learning the front end the first time. Ecosystem and community matter for adoption