Scientism is a pejorative term, a lie, beloved of religionists and their sympathisers which is used to prejudice religious believers against science they don't like

In the religious vocabulary, scientism is an insulting word to describe the view that science is the only reliable way to know anything, that anything that science cannot answer is not worth discussing - eg morality and religion. Scientism is said to be hostile to anything that isn't scientific - it is called bigoted. In fact if such biased bigoted scientism exists, its bad effects are minimal and its servants are few. Usually if science comes up with some truth that religion despises, it tries to call it scientism in order to make it look bad. Religion accuses science of going across the boundary into religion where it does not belong but religion itself intrudes on the realm of science.
Hard Scientism is the belief that the only truths are those verified by science and that there is no reason to believe anything else. It doesn’t claim that scientific truth is the only truth. It only claims that scientific truth is the only believable truth.  Nobody at all really holds that view.  If you believe all that matters is what you know then you will not try to know more for there is nothing there to know.
Soft Scientism is the belief that there is reason to believe things that are not verified by science. But it teaches that science is the best way to discover truths. It teaches that science is the most authoritative way.  This however is only mere science.
To describe scientism is to see that it is correct and does not really involve bias. It is science not scientism.  Religious belief cannot be as important as testable scientific belief. That is why so-called scientism is right. It is that simple.
Science is about observation and reporting it. It does not have an agenda and when it does it is not science. There are better suspects for having an agenda than science!

A science theory, to be valid, must explain everything but it cannot do that if paranormal or godly or spiritual powers can tamper.  Even if they do not tamper they still look as if they do and that is as bad.

Religion tries to make out that science is or can be dogmatic and bigoted against religion and refuse to learn from it. It calls this scientism to avoid the charge that it is attacking science.

Science is about questions and these questions are invariably sceptical. It is like, “I will not believe this unless I have to on account of the evidence.” Science is not belief in the normal sense but critical belief that it continually tests and challenges. Religion says that scientism dismisses religion and does not care about the evidence for it.  But any science that does not care about evidence is not science.  Good science is always labelled as scientism when the believers do not like its findings.
Science does not hate anything that is not scientific. It just ignores it. It does not say that science alone gets at the truth. There are truths that science will never verify but which are nevertheless true.
When people say science is a faith even if not a religious faith, they are referring to the fact that science has faith and belief that nature will work a certain way - it is orderly and regular. But science is based on experience and on doubting that experience and checking it out rather than belief and faith. Science tells you what will happen in the natural world and it happens. Science observes the universe and how it works - it is not making assumptions.
Is it true that science has faith or belief in reason? Some answer that reason for the scientist is a tool that works and that is all. You do not need to believe in the existence of your screwdriver to use it. A mad man who believes there is no screwdriver in his hand though he senses that there is could still use it. If you think a calculator is always wrong that will not stop you getting the right answer as long as you follow the instructions.
Some religious people say that when science acts like a religion, a conflict will appear with say Christianity. They seem to mean something like this. "Science cannot prove that Jesus rose from the dead even if he did so it is a religious truth - if it really happened. But when it enforces the view that Jesus did not rise, it is acting like religion in the sense that it is putting forward doctrines that are not scientifically verifiable." If scientists become religious in that way, if their unbelieving dogmatism can be understood as religious, then that creates an interesting problem. Should such scientists have the same rights as religion under the law? If science makes dogmas out of what has not been tested then that is not science. That is the bottom line and the religious people are setting up a straw man.

It is said that science cannot give us morality or something that is an okay substitute for it.  Because of that religion holds that caring only about evidence and experiments undermines morality. It calls that scientism. But it is science.  Science gives you a ought and without an ought you cannot even think about moralising or working out what is morally right or wrong. Science does have an ought – stick to observation. This is so reasonable and simple and we must see that condemnations of "scientism" are just nasty.
Those who oppose scientism as they call it seem to have a problem with science stating its teachings are factual. They would deny we know anything before they would let the truth and honesty of science refute or threaten their faith.

Science would need less funding if it were not for religion's lies.