Shortened Life Span: Light Bulb Conspiracy

Have you ever wondered that the things that you buy do not last long? Is it just us as consumers who use it recklessly?
Have you ever thought that it is actually the producers that make it that way?
To illuminate this, there is a documentary about light bulb conspiracy.

Before, light bulb is created to last more than 2000 hours. Now, it is only for 1000 hours. What happened? Isn't it supposed to be longer since the advancement of technology? Not only light bulb, the other products such as printers and stockings are designed not to last long so the consumers keep buying the products. Do you think this is ethical?