alt Hacker NewsYou forming a personal opinion after years of interest in the subject is fine. You asserting that opinion as a fact is the problem.
It is a tale as old as time. See the story behind the term. ultracrepidarian: https://en.wiktionary.org/wiki/ultracrepidarian#English
Versus https://en.wikipedia.org/wiki/Argument_from_authority
See also: https://www.science.org/content/article/potential-fabricatio...
Amateur's asserting their opinions as facts isn't great, but epistemologically it's no worse (and systemically, like less harmful) than when the experts do it.