The legal doctrine of fair use is pretty fair, in theoretical terms at least.
But YouTube/Google's extrajudicial approach to it is at best arbitrary, and often abusive.
It's contrary to the objective of intellectual property rights — which that the People grant an artificial monopoly on creative work, with the goal that it will benefit society at large.
By stifling criticism, comment, news reporting, teaching, scholarship and research YouTube, Google and others work directly against that societal goal in the name of industry rent seeking.