Most conspiracies are explicitly irrational for two reasons, one of which is especially relevant to your point.
1) They don't have evidence to support them. They are stories, backed little to nothing.
Many have little evidence, available. But that does not make them irrational. If someone insists that they “know” something to be true without evidence, that would be irrational. Believing that the official explanation is less likely to be true than an alternate explanation, based on past behavior by the officials in question, is rational.
2) They're contradicted by evidence. Which the conspiracy theorist ignores.
Sometimes they do. I agree that is irrational. Remember that the point of the OP was not that ALL CT’s are by definition true.
If the 'government' is hiding evidence, then conspiracies fail on the first point. Without evidence, they literally fill in the gaps with their imagination. And you get crazy ass stories like particle beams in orbit shooting the WTC, North Korean submarines sneaking in fake ballots through Maine, 'Q-Drops', or the entirety of the J6 riot being caused by some dude named 'Ray'.
If you are admitting that government hides informationn (and how could you not?), you are agreeing that there are conspiracies. It is true that when government is successful at hiding information, then it is difficult to know which particular theory about a conspiracy is the right explanation for what the government is hiding.
You’re being very specific in which conspiracy theories you claim are evidence-free. Do you plan to address the three important recent examples I described?
I’m surprised at the last one. I assume you are exaggerating your claim of what the Ray Epps conspiracy theorists believe. They believe that he was an FBI informant sent to encourage violence on Jan 6th. Ray Epps is on camera encouraging Trump supporters to enter the Capitol. The Trump supporters say “nooooo!” And one of them starts a chant of “Fed! Fed! Fed!” That’s pretty strong evidence that Trump supporters wanted to be peaceful, and that Ray Epps wanted them to enter the capital.
He was on the FBI’s most wanted list and then taken off of it and never arrested, with no explanation for that contradiction. That is evidence that he was treated differently than other people who were near the Capitol that day. That he was working for the FBI is a rational idea, and of course the FBI would never reveal any evidence if he was. I believe you are smart enough to know that “evidence” is not the same as “iron-clad proof.”
Maybe he wasn’t an FBI plant when he said “tomorrow we go into the Capitol.” Maybe he saw his name on the most wanted list, got scared, and turned himself in, and cooperated. That’s another rational explanation for what happened with him. But we will never know, because the FBI will never tell us.
The FBI has a record of conspiratorial and criminal behavior. Suspecting them of it now is not irrational. Especially when they come before Congress and stonewall.
What you call 'common sense' is people using their imagination in place of evidence. Literally just making shit up. And there's little sense in it.
It is indeed common sense when people suspect the worst from people who have been proven bad actors in the past, and are now hiding information.
People use their imagination to come up with theories all the time. That’s how innovation works. That’s how knowledge increases. “Imagination” is not a dirty word.
As demonstrated elegantly by point 2: the conspiracy theorist's irrational denial of evidence, ignoring all the evidence that contradicts them and replacing it with......you guessed it....
.....their imagination.
Some people do that, yes.
It is educated guesswork and estimates of the situation in many cases. We are allowed to learn from the past. When presented with unlikely explanations of events coupled with failure to produce evidence, our choice is to believe the unlikely, in spite of lack of evidence, which would be irrational, or to hypothesize on what the true explanation might be.
Worse, once you've got your ticket on the 'replace evidence with your imagination' train, then anything that contradicts you gets folded into your conspiracy. With the conspiracy getting more wildly elaborate, more ludicrously complicated, and more inherently fantastical.
The audit contradicts you? Well then the republican lead election board must be in on it too! A court rule against you? Then the judiciary has to be in on it too, they're nothing but corrupt judges! The Republican Secretary of State contradicts you on election fraud? Well then the GOP must be part of the Deep State and conspiring against you. The Republican AG contradicts you on election fraud. Why then this must go up to the entire Department of Justice! The whole government! They're all in on it!
There's no sense in any of that. Common or otherwise.
Yes, if taken that far, it is irrational.
What about the three hoaxes I mentioned that were perpetuated by government officials who are still in power?