The art of bad design

In the course of my life, I have used some ten different vacuum cleaners, if not more. We all use vacuum cleaners, and we all know what the common issues with vacuum cleaners are.

1. The power cord.
   The cord of a vacuum cleaner tends to get tangled when you use it, and because it's longish, it gets tangled when you store the machine in a closet. That's why modern vacuum cleaners have a system that retracts the cord when you push a button or when you jerk the cord. This works fine on all vacuum cleaners. That is, it works fine when it's new. But lets consider your average three year old vacuum cleaner. My Dyson currently is two years old, and when I store it, the cord sticks out by about a foot. And this is ok, because in all other cleaners, it was worse. The cord retraction was tested with new cleaners. Apparently they don't test older machines.
   
2. The wheels.
   A vacuum cleaner has two big wheels, and a small caster. This causes the device to follow your movements and not topple. The caster hops over the cord most of the time, it doesn't get stuck. As long as it's new. After a few years, or even after six months, the caster wears out, and it does get stuck when it hits the power cord. I've had a vacuum cleaner with a fine looking caster, made out of plastic, it looked like a half sphere with a little wheel sticking out. It stopped moving after half a year, and when I took it apart, every idiot could see that it couldn't have lasted long. It was badly designed and badly made. I replaced it with the cheapest and simplest caster from the hardware store, which outlasted the rest of the vacuum cleaner. Why didn't the manufacturer put in that caster? Is it because it would have added one euro to the price?
   
3. The hose.
   When you walk around pulling the vacuum cleaner, you know that the device has a tendency of falling backwards when you pull it in the wrong direction. Which you do because you don't pay attention. Manufacturers come up with all kinds of solutions for this, and when you test your new vacuum cleaner, you're happy because it works perfectly well. But the connections between the hose and the device wear out quickly, or they get stuck because dust is collecting inside, so my two year old Dyson does topple when I make a wrong move. Which is stupid because if Mr Dyson would have spent an hour a week using an old vacuum cleaner, he'd know what the issues are and he could have started looking for proper solutions.
   
4. The brush.
   I have cats. Cats drop mountains of hair in your home. Which you have to vacuum out. My vacuum cleaner, like all of them, has a brush with hairs on the edge and a whole that sucks in the middle. The cat hair gets sucked towards the brush, and it gets stuck between the floor and the brush, outside the brush, so it can't be sucked up into the machine. Every two minutes, I have to pause and remove the cat's hair from the brush. Mr Dyson apparently doesn't have cats. Or he would have made the brush inside out: it would have brushes that it rests on in the middle, and it would be sucking at the edges.
   

If I can think of that, why can't the average designer of vacuum cleaners? One thing I know. Vacuum cleaner designers don't do the vacuum cleaning at their place.