Its a great language and easy to learn and use, but it might greatly limit their business relative to AWS.
I polled HN about a month ago to see what percentages of HN readers used what languages for web development, and while Python was the most common, its still only used by 22% of those polled. Take this data with a grain of salt, but still an interesting statistic:
It's not even the choice of python that's a limiting factor, its that you don't have a full server, just a language sandbox. Still it might be a great place to start a web application.
Why? The Google "big 3 language" choices are Cpp, Java & python ~ http://panela.blog-city.com/python_at_google_greg_stein__sdf... You may see perl or other languages but the "big 3" are the officially supported ones.
"... python ... but it will be a non-starter for many developers. ..."
I find that an interesting statement. Why say that? Python is a pretty easy language to learn & use.