> Isn't this just an anti-science term adopted by religious people and postmodernists?
Not at all, as a scientist, I find scientism to be very common and the biggest obstacle to the general public understanding science- more so than religious people and postmodernists which are at least openly anti-science, rather than just confused about what it is. It is a fanatical religious like belief in the correctness, completeness, and finality of "what science has already discovered" and an aggressive dismissal of e.g. things like creative though experiments or anecdotal observations that question current understanding. To people practicing scientism, the regular practice of actual science looks like heresy and pseudo-science and they would get angry if they were present, e.g. when Isaac Newton or Charles Darwin first mentioned their now accepted but once controversial ideas. They will say things like you don't know (and shouldn't think or talk about) anything until it is confirmed in a large study- without considering how scientists come up with the designs and ideas (and funding) for such studies in the first place.
Science in popular media and schools is taught as a bunch of authoritarian facts to memorize and believe without deeply and intuitively understanding, rather than a creative process of trying to deeply understanding and question things for yourself. When I mention something interesting or counter-intuitive I encountered in my professional research, or something interesting I have been thinking about recently- especially among young intelligent "skeptical and science loving" non-scientist programmers on this forum, I am often met with angry derision, because the process of talking about and exploring weird ideas- e.g. the actual how the sausage is made by working scientists, is seen as extremely unacceptable if it conflicts with what they heard in school, media, etc. I’ve mentioned things I’ve personally discovered on here- and been called an idiot and sent the wikipedia link for a field I’ve studied for decades, and is actually citing my older papers and work, by someone that only heard the field existed when they read my comment.
The pseudo-science conspiracy theory people ironically get the creative independent thinking part more right than the "Scientism-ists", but then miss the important second part of actually taking the responsibility to deeply understand for yourself, and critically question things.
There is something very wrong with science education when the people that say they love it, respond negatively when they encounter the real thing- and this can be fixed by redesigning science education. As an academic PI I don’t teach regular classes, but put students directly in the lab working on a new problem nobody has solved before, where they can’t look up the answer, and then mentor them 1 on 1 if they get really stuck. I then have them actually write it up and submit it to a real peer reviewed journal.