How did the term “skeptic” come to mean “people who believe in multiverses, space aliens, and random creation of meaningful information?”Good questions. It's a source of wonderment, at least for me, that "skeptics" often deride theism and theists for believing in God, for which belief there is much evidence, while themselves believing in such things as an infinite number of worlds, the inevitability of the emergence of life by random chance, the reducibility of consciousness to chemical reactions, the possibility of non-subjective morality without God, the inherent goodness of man, and a host of other naturalistic dogmas for which there's scarcely a shred of evidence for and much evidence against.
How did the term “fundamentalist” come to mean “people who believe based only on evidence”?
Atheists are often wont to say that religious faith is belief despite the lack of evidence. That's not true, however. Belief without evidence is the definition of "blind" faith, and it describes belief in such things as other worlds and abiogenesis perfectly. The faith that religious people cling to is not belief despite the lack of evidence, it's belief despite the lack of proof. As such it's completely rational, indeed more rational than the belief of those who will accept any explanation, no matter how meager the evidence, as long as it doesn't violate their commitment to a non-theistic metaphysics.