It all boils down to inherent insecurities and unhappiness, and picking on a person who is obviously happy with his life and passionate about a few things. Yet, the so-called adult will project how great his life is, when in reality, he is unhappy and needs to project and put down others to make himself feel better. I run into a lot of these types outside of my professional career. I used to try to challenge them and argue with them, but it is mostly a useless and frustrating exercise.
He is a climate change and science denier. Anything that comes from those two worlds create an immediate reaction to refute and be scoffed at. It’s both ignorant and dangerous.