That was a quotation *from* Peterson! That said I kind of agree with part of the substance of what you say, namely that any attempts to give nice neat summaries of complex historical movements is going to miss things out. Trying to say something sweeping about millennials, or about postmodernists, or about Romantics, is always going to miss people out. The hope is that despite this, there is enough commonality to the people the various terms pick out that we can use them to provide semi-decent explanations of cultural phenomena.