I suspect you are mostly right in that many are more concerned about funding - and publication - at the micro (personal) level, and this might discourage many f

I suspect you are mostly right in that many are more concerned about funding - and publication - at the micro (personal) level, and this might discourage many from going against the establishment armed only with speculation. As for the scientific establishment (eg the NIH in the USA), it is very politically aware and was apparently determined to speak with a single voice. Somewhat ironically, this may have made it impossible for them to put an end to lab-origin hypotheses, even if they are false.