Your question is significant, even profound. I have contested the views of some over Psychohistory and just what value should be placed in what I refer to as the 'Asimov Orthodoxy.' The first part of this is the 'addiction to prediction.' Many consider prediction to be the primary aspect and I must disagree. It is not the prediction of the future we need, but a way of making the future come out the way we wish. That in itself is quite a task-what do we want to happen? Next is the obsession with Physics models. I have carefully looked at the proposition of using Physics models with respect to human societies, and I don't see much of a connection (see a book called "Critical Mass"). The subtleties of Asimov's book is found in the placement of societies in key locations, not some romantic notion of people behaving like a 'gas-molecule model.' Another, often overlooked, aspect is the ideal of reducing needless human suffering. This is really the whole point of Psychohistory. In creating models, we must not be the slave of an idea, but the master. Models reflecting human societies must understand the behavior of societies. Policies flowing from such models are more likely to succeed than a wishful attachment to models that do not apply well.