'Scientism' is a scare word. Its chief purpose is not so much to describe a position as to describe-and-attack. It is generally used by those who are ill-disposed to what they see as a narrowly scientific view of the world to suggest that there are other sources of knowledge than ordinary human perceptions and judgements and the empirical and deductive methods of science and mathematics.
Many thinkers take human consciousness (which of course incorporates value judgements, etc.) as a window into something like a spiritual or moral realm, but I would have thought that our perceptions and judgements are entirely the result of processes associated with individual organisms interacting with each other and the wider organic and inorganic environment in which we find ourselves.
The fact that mathematics seems to subsist in a world of its own - accessible to human reason and not empirical in the normal sense - poses problems for radical empiricism, but computational approaches to mathematics (incorporating the concept of information as something physical) may lead to a natural way of sustaining a physicalist, anti-Platonic outlook.
The very fact that we have so many alternative philosophies of mathematics and no clear way to decide which of them (if any) is 'true' suggests that the traditional categories and concepts in which these competing approaches have been framed might be the real source of confusion, and that radically new ways of addressing the questions are needed.
The trend certainly seems to be towards seeing mathematics as being rather closer to physics than has previously been thought to be the case.
Our knowledge of the world may conveniently be divided between ordinary, everyday knowledge (incorporating skills, commonsense, values and so-called intuitions) and theoretical knowledge. The latter is valuable in my view only to the extent that it is scientific (broadly interpreted).
If this is scientism, I can live with it.