That doesn't make sense and is a blanket-statement on your part while severely over-generalizing things. How could a "conspiracy believer," as you put it, usually either be stupid or dishonest? Most people search for the truth because they are against dishonesty, corruption, cover-ups, etc. And most are the opposite of dumb but usually quite sharp, articulate, and analytical.
BTW, "conspiracy" just means there is more than 1 person involved. To say someone who believes in conspiracies is stupid or dishonest is like saying that someone who believes human beings lie must be stupid or dishonest...Only a person who is stupid or dishonest themselves could actually believe such a statement in the first place.
There are even laws specifically to charge people and put in prison for committing a conspiracy. Haven't you ever heard of people charged for "conspiring?" Saying there are no such thing as conspiracies is like saying there are no such things as humans lying; it's so far beyond ridiculous and ignorant.
Conspiracy theories are all well known fakes, if you believe in them then be it, it isn't my problem. Also if you think those, who believe in conspiracy theories are sharp and analytical, that is ridiculous.
People lie of course, that is why they are dishonest if they do. If they don't know that they were lied to then they are usually can't differentiate between facts and fiction or in some cases delusional, which can be the third option I forget in my previous post.