Why is it that the opinions of conservative/ right wing voters who are now expressing doubt and criticism for the current admin are completely written off as paid Democrats?

I’m mainly referring to the recent townhalls full of angry constituents in red districts. They were written off as Democrats who were paid bad actors to make the administration look bad.

Despite there being absolutely 0 proof of this, it was immediately accepted as fact. Why is it seen as impossible / improbable that any conservative would ever dare disagree with him? No matter who is President, in every election, Republican or Democrat, there are bound to be some voters who regret their decision in hindsight for whatever reason.

So why aren’t conservatives allowed to disagree with him, especially if they were directly impacted by his decisions , I.e. Veterans dependent on the VA or any other federal worker. Plus, some would even argue that Trump is not conservative at all. I just can’t wrap my head around the fact that those constituents were immediately written off as paid actors with no proof and everyone just accepted it as fact.