Conspiracy theorists are people looking for deep meaning in the trivial. Because their lives are trivial and missing meaning they crave.

A good point, though it's never safe to ascribe the same explanation to all in a very large group.

I think some others crave deep, complicated or spuriously exciting meanings because they are unable to cope with real but usually very mundane explanations.

Some might not have the courage to say honestly, "I do not understand...", so invent or fall for strange "explanations" that frequently cannot withstand simple logic, let alone detailed, real knowledge of the case.

Whilst others of course, have some malevolent reason for wanting to spread ignorance, even downright lies.