Myth:
Fundamentalist atheists don't appreciate mystery and beauty in life because they treat science as a source of rigid truths that cannot be challenged.
Response:
It's not a coincidence that allegedly "fundamentalist" atheism is being paired with science here because this is basically the same complaint which some religious theists — and perhaps some of the same religious theists — make about allegedly "fundamentalist" science itself. Whether the target is atheists or science, the basic claim is the same: subjecting empirical claims about the world to rational, methodical scrutiny removes magic, mystery, and beauty from the world.
For the most part, this myth is completely false. There is nothing about atheism or science which is contrary to appreciating or enjoying beauty in the universe around us. On the contrary, an appreciation of beauty in the universe is often an important impetus behind people becoming scientists and, in some cases, atheists. Science explains things which people don't understand and atheists who insist on using science are insisting on learning how things work, but an understanding of how things work cannot eliminate beauty from the world around us. It can, in fact, lead to a better appreciation of that beauty because now you know where it comes from.
In some ways, though, there may be a grain of truth to this: science does try to eliminate mystery because it tries to provide answers. I am at a loss to understand why that's a bad thing, though. Mystery has value insofar as it causes us to try to discover answers. Who can or should value a mystery without also valuing answers? Attempts to promote mystery without also promoting attempts to find answers is really the promotion of anti-intellectual ignorance. It's an attempt to say "we don't know some answers and that's good — we should not only accept our ignorance, but we should prize it and denigrate those who would dare to try to find answers to our questions."
There is nothing even remotely "fundamentalist" about trying to find answers to our questions, but it's not surprising that people who value their ignorance would get upset if those who value knowledge try expand what they know and learn more. It's wrong, however, to claim that science is treated as a "source for unquestionable and rigid truths that can't be challenged." That's exactly the opposite of what science is — in reality, science is a method for discovering what is more likely true as opposed to what is more likely false. Far from being rigid, science is always open to new data, new research, and new information that forces us to change our conclusions.
Of course, to understand this a person has to value new information, new research, and new data. A person has to value knowledge over ignorance, which is precisely the opposite position of those who promote the belief that there is something wrong with atheists or science for seeking to solve mysteries. Isn't it curious that a person would on the one hand promote anti-intellectual ignorance as a positive value, but then misrepresent science as something that doesn't oppose ignorance?
The reason for this contradiction may lie in the fact that the problem for such religious theists isn't so much how science or atheists try to solve "mysteries," but in how science and atheists try to offer naturalistic, materialistic explanations for the religious beliefs, claims, and "mysteries" which theists cling to. Many religions require the truth of miracles and other supernatural claims, so the existence of alternative explanations effectively undermines the ability to believers to insist that their positions are necessarily true. Instead of directly addressing and trying to refute those explanations, however, believers here focus on alleged motives or qualities of atheists in order to encourage others to dismiss what atheists have to say.
