That is true of all of science. No theory in science is ever proven. All a scientist can do is collect data that tends to support the theory. But that is not a proof. The sticker seems to be quite accurate. I think they should put it back on the books.
So you are basically anti-science? That's what that sticker infers based on your interpretation. And you are right. Theories in science can never, ever be proven. There isn't a single theory in any field of science that has been proven true. If you knew why, then you would show an understanding of science and the role of theories therein. As science advances , theories also evolve and adapt. That's what I like about science - as we learn more, our understanding advances. It is a very common misconception that answers from science are an absolute, unchanging truth. That being said, the only thing science can do is disprove. Thus far, evolution has not been scientifically falsified.
Well if science teachs that the earth is flat, does the earth flatten out to suit science? No of course not.
The point is they should not teach anything as an absolute in science, first thing it does is close minds.