Whether you believe science can or can't prove that God doesn't exist, it doesn't matter, as that is the belief that the majority of atheists and secular scientists have adopted. At least the vocal minority. It is also that belief that has been treated as fact in schools and colleges around the world.
You seem to be listening to the prejudices of others here (added: This was poorly worded. I meant that you may have been listening to others when you wrote this, not that you were listening to others here on the site). Schools and colleges, as you say, teach science as we know it, and as we theorize it. They don't mention gods because none have been found in the various forms of research done within the scientific disciplines.
What do you want science teaching to be like? "This is how photosynthesis works, except somewhere in there a god is involved, we just don't know how. But be prepared to answer questions about him on the test." Is that what you prefer?
We know so little about reality that all we can do is try to figure out the stuff we experience and then extrapolate as far as we dare about other matters. That thousands of gods have been proposed, and none proven, means that either we ignore that contention or we figure out a way to add the christian and hindu and zoroastrian and aboriginal and native American and other gods to the curriculum and make stuff up as we go along. I have no idea what that would accomplish.
Now if you're upset that the physics folks working on the edge of knowledge aren't trying to fit god into the equation, that's fine. Just go get yourself as educated on physics and then come up with your own theory that includes deities and such. And let the scientific world try working out the specifics of your theory. But as of right now, even as mysterious as the universe it, there is no sign that gods or the supernatural are involved.
There are great mysteries, that perhaps can only be solved by gods or supernatural powers. We don't know that, but it is a possibility. We are still early in the learning process. The problem for theists is that as of now, we haven't had to invoke gods to explain anything quite yet. Our math doesn't show any, and our machines haven't discovered gods yet either. So we are forced, by default, to study only that which we can find evidence for. Anything involving gods would just plain have to be made up. I've no idea how one could work salt ladies into chemistry class, the flood into geology class, Eden into biology. Let alone biblical astronomy into the modern version of the subject.
If there are gods or the supernatural, they apparently don't want to be found, and prefer depending upon poorly passed-on ancient documents to supply all the knowledge of such things. Which, unsurprisingly, fail to meet any reasonable modern standards.
And an aside. If the earth was created in six days, 6,000 years ago or so, it sure shows no sign of either that speed or that age. Nothing science can find matches that story, and in fact everything found contradicts the tale. Nor is there any sign of floods or Babel or other audacious claims. And there is planty of evidence for the current theories about the age of our planet, which is that it is approximately 7,500,000 times older than the bible claims. Or the universe, which is almost 2,300,000 times older, as per all the evidence we can find.
So there are some of us that look at such evidence, and combine it with other insights, such as the lack of proof from any other sources regarding either gods or purpose, and draw the conclusion that the universe is a natural place, and here only for the natural physical reasons that caused it to exist, and no other explanation or rational is required. I am not so stupid as to assume that that assumption is absolutely correct. I am just saying that as of right now, I see no reason to think otherwise because any proof of other reasons/origins/god involvements are as of right now, non-existent.
And while I could spend my life guessing my ass off about what is going on, without any information to go on, all it would be is guesses. Or a decision to include ancient belief systems in my modern life. And I happen to be one who is not so inclined.
If religion had something definite to offer, like usable information or claims that were not so far from being reasonable, I would sit up and listen, but until a religious story comes along that matches observed reality, or successfully explains it away, I'm going to go with scientific findings and my own version of rationality over the myriad imaginings of others.