These, of course, are not problems with Ruby -- so fellow Rubyists, don't get bent out of shape over this. It's a list of his priorities, which don't happen to align with the current state of Ruby. It's not hard to come up with a different set of criteria that make Ruby look perfect and Python look unusable, and I'm sure other people here will do just that.

But interestingly, all three of his main arguments in favor of Python (more mature, more consistent, and more complete documentation) also sound like great reasons to use Common Lisp over Python.