Hey parts vendors, how about INCLUDING A DECENT SET OF INSTRUCTIONS in with the products you sell?

If you mean this, then you are the problem. Maybe the way you write your instructions are worthless.
READ the comments in this thread. There are people that DO read directions and if you don't include them in the packaging with the products,, you are doing them a disservice.
Hire an expert...screw that. If your product has multiple components yet don't come with directions with measurements and helpful tips, you are worthless to many customers.
Your terrible suggestion at the bottom shows your arrogance and lack of respect. YOU are the very inspiration for this thread.

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.