The evidence of where the outbreak originated, i.e. a wet market in Wuhan, and the genetic characteristics of the virus, i.e. clearly traceable to identical viruses in the original host species, are very strong indicators that it was not 'created' in a laboratory.
So, whilst it may, in the strict usage of the expression, be 'completely conceivable', I take exception to your use of the word 'naive' to describe people who dismiss the idea. I would say it is entirely rational to follow the evidence and draw a conclusion based on that evidence.
You might argue that it is immature to be incapable of understanding the probabilities of certain events or sequences of actions.
Originally Posted by: Gandalf The White