I feel that the reasons why many folks fear the doomers are multifaceted.
IMO the following provides a big piece of the puzzle.
Terror management theory"TMT is derived from anthropologist Ernest Becker's 1973 Pulitzer Prize-winning work of nonfiction The Denial of Death, in which Becker argues most human action is taken to ignore or avoid the inevitability of death. The terror of absolute annihilation creates such a profound – albeit subconscious – anxiety in people that they spend their lives attempting to make sense of it. On large scales, societies build symbols: laws, religious meaning systems, cultures, and belief systems to explain the significance of life, define what makes certain characteristics, skills, and talents extraordinary, reward others whom they find exemplify certain attributes, and punish or kill others who do not adhere to their cultural worldview. On an individual level, self-esteem provides a buffer against death-related anxiety."
https://en.wikipedia.org/wiki/Terror_management_theoryThe Denial of Death by Ernest BeckerAn explanation of the book and terror management theory
https://www.youtube.com/watch?v=9Hi1C4NNnV4Sheldon Solomon - Ernest Becker & The Denial of Death"Terror Management Theory (TMT) was proposed in 1986 by social psychologists Jeff Greenberg, Tom Pyszczynski, and Sheldon Solomon. The theory was inspired by the writings of cultural anthropologist, Ernest Becker, and was initiated by two relatively simple questions: Why do people have such a great need to feel good about themselves?; and Why do people have so much trouble getting along with those different from themselves?
The basic gist of the theory is that humans are motivated to quell the potential for terror inherent in the human awareness of vulnerability and mortality by investing in cultural belief systems (or worldviews) that imbue life with meaning, and the individuals who subscribe to them with significance (or self-esteem). Since its inception, the theory has generated empirical research into not just the nature of self-esteem motivation and prejudice, but also a host of other forms of human social behavior. To date, over 300 studies conducted in over a dozen countries have explored such topics as aggression, stereotyping, needs for structure and meaning, depression and psychopathology (e.g., phobias), political preferences, creativity, sexuality and attraction, romantic and interpersonal attachment, self-awareness, unconscious cognition, martyrdom, religion, group identification, disgust, human-nature relations, physical health, risk taking, and legal judgments."
https://www.youtube.com/watch?v=XpVkrIdz9-Y