Heh, I mentioned my dyson problems to a repair place and they said "die-soon" and laughed. They do have a somewhat innovative design, but are made almost entirely of plastic and just don't last very long.

Sure it's kind of cool to skip having to have replace vacuum bags, but it's much more of a pain to have to replace the entire unit because of a relatively minor problem.

So I think it's mostly just good marketing and attractive products and consumers who don't look at the reliability/expected lifetime before purchase.