I do mean it. It doesn't matter how foolproof we make anything, the majority are simply bigger fools.
The cost of making detailed manuals is often higher than development a good product, and if that manual doesn't save enough in customer service costs then it's simply a waste of cash.
Since most folks won't read instructions and the rest are illiterate, the math is easy.
The "problem" is that too many fancy themselves far more capable than they really are. There's nothing that can't be figured out by anyone with a three digit IQ and a few hours (or days in some cases).
If a few hours to look at and understand a system is too much, take up knitting.