Science is the study of what is measurable.
Scientism is the belief that the universe can be fully explained by science.
If consciousness is measurable, then it is the proper object of study of science. Philosophy and all forms of spiritual belief are irrelevant superstition.
The possibility that consciousness is not measurable is rejected by the followers of scientism; since they do not admit the existence of anything that is not measurable.
If scientism is wrong; then there exist things that cannot be measured. Consciousness is one of them.
By measurable, in this context, I mean to say something that is perceivable to the human senses, either naturally or augmented by human devices (microscopes, particle colliders, etc.)
If you believe in the existence of non-measurable things; you are marginalized and labelled a spiritualist.
I believe, though, that it is possible to be a big fan and supporter of science; while rejecting scientism; and accepting that there are things we just can't measure.
Yet we can still know them. Look around! Look at the miracle of life. Look at your own consciousness. It's something beyond the chemicals sloshing around in your brain. This I believe.
I believe in science. I do not believe in scientism. I believe there are things that can't be measured; but that can yet be known by us.
To respond directly to your question, which I take to be, What are the advantages of scientism; well, lately, it's political. I noticed that during the run of the recent Cosmos program with Neil deGrasse Dyson, some liberal-oriented websites took special glee in tweaking the beliefs of religious people. Dr. deGrasse Tyson himself likes to tweak the beliefs of religious people.
He's not very keen on philosophy, either, as you may know. He thinks it's obsolete and irrelevant. But of course that is a perfectly rational point of view to take, if one is a believer in scientism, and not just science.
But what other advantages? Well, scientism serves the human ego's belief that we can know the universe. But what if we can't know the universe? That upsets some people so they deny the possibility.
In Steven Weinberg's popular physics book Dreams of a Final Theory he said that his goal was to be able to explain the entire universe with an equation you could wear on a t-shirt.
That, I claim, is the essence of the answer to what advantage scientism holds. That we could find one simple perfect principle that explains everything. Tie the universe up in a bow made of logic.
Of course anyone who knows the first thing about life knows that the universe can not be tied up in a bow made of logic. Logic has limitations, as we discovered in the 20th century. And many great scientists do actually understand that all they are doing is describing; not explaining. Newton was explicit about that. But, some scientists are also believers in scientism. And perhaps that certainty or intellectual arrogance is a helpful attitude to have if you are trying to figure out the secrets of the universe.
The best reason to believe in scientism is that there's a lot of it going around these days. Books espousing scientism litter the best seller lists. The New Atheists and all that. I'm sure if Christopher Hitchens is looking down on us right now from heaven, he's mighty annoyed about it.
By the way there is a classical argument in favor of spiritualism (the negation of scientism). It's called Pascal's Wager.