Assembly Required

Why is in this day and age when you buy a product, it is required that you assemble it yourself? This typically includes such items as bicycles, grills, bookcases, picnic tables, storage cabinets, etc. Recently, this extended to a file cabinet that I purchased. After spending about $200 for this piece of furniture, it was wrongfully assumed that it would be delivered already assembled. No, it arrives in a flat box with a zillion pieces and directions that appear to be written in hieroglyphics. I admit to not being mechanically inclined and thus it took me over three hours to assemble this cabinet and other half an hour to clean up all the plastic packing material. By some miracle, I did finally get it together but how about all the other times that I or others have not be able, or found pieces to be missing, or fastened something incorrectly, or ended up with extra pieces requiring a disassemble and reassemble. I know the argument is that assembled merchandise would cost more but there are times I would exchange paying a little more for something rather than to spend hours of my time on something that may or may not result in a properly assembled product. I know this rant is not going to change the nature of business but it makes me feel better. Now what is the purpose of this hardware that I have left over and where is my cat?