Python has much better support for data anlysis/machine learning, but, honestly, I don't hear about django or other python web frameworks anywhere as much as I hear about rails. Have you got a source for your first point?
As a counterpoint: I never hear about rails being used for anything, except maybe GitHub. I personally also don't know a single person that knows how to write code in Ruby. We both might live in a bubble.
It was an impression of mine, but it seems it was just bias of availability because I heard some bootcamps were changing Rails for Python.
But I believe I was wrong on this one. A quick search on a page I googled for "best coding bootcamps" led me to this page[0] where a quick ctrl-f showed the results: Ruby = 34 results, Node = 18, Python = 12.