|How often has this happened?
You are just finishing presenting a tightly reasoned argument. Your
facts have been well documented.
Someone stands up and says "In your opinion" and with this remark the
discussion is terminated.
What they are saying is that all opinions are equal and therefore fact
and reasoning are irrelevant. How convenient this position is. It is not
necessary to find flaws in arguments, or check facts. This position is
the natural home of the unprincipled for precisely this reason.
How could Galileo prove the Copernican system against a flat earther
who shouts "In your opinion"? Unless one is prepared to agree with the
flat earthers, it follows that "in your opinion" is not a refutation.