Earlier quoted context omitted.
Gait control is widely recognized as on-topic in AI robotics circles. There are sessions on this topic at the main conferences, for example.
Well, yes, but getting robots to move without falling over is not really a core AI topic; it's an application area where some AI stuff happens to be useful. Coming from a site with a name like "Open AI" I expected some software to help promote research on workhorse AI topics such as search, planning, constraint programming, knowledge representation and automated reasoning.
Animals solve the problem wonderfully every day, using (at least partly) their brains. That's a working definition of an AI problem.