Fascinating topic with much food for thought. I see two phenomena at work in this area.

First, many people(s) seem to be most uncomfortable accepting the existance of something unknown. Such difficulty might flow from any number of sources. Whatever its origin, it creates some degree of angst, and the simplest way to resolve that angst is to create an "explanation" for the unknown, thereby converting it to "known". As but one example, consider the way in which many religions anthropomorphose their various conceptions of god(s). It seems that if we put a human face on a thing, it is easier to accept and embrace. A marketing person might call this the "familiarity factor."

Second, most people seem to be unfamiliar with statistical concepts relating to causation. I learned them as the three "Cs": coincidence; correlation; and causation. In the case of co-incidence, the fact that two things occur together simply means that they occurred together and does not imply causation. If those things occur together often enough they are said to be correlated, and when that correlation reaches a high enough level there is a basis for probable causation. When that correlation is absolute, such that A & B always occur together, then we can think of causation. Not necessarily that A "causes" B, but that they are causally linked.

The "three Cs" are a good filter mechanism for the rational skeptic.