Thanks for the answer. However I am not talking about the product's warranty. Perhaps an example will make it clearer.
Fruits have a limited life span, once they are picked from their tree. They are sent to grocery stores, that sell them to consumers.
Let's say you walk into a grocery store, and see rotten fruit. You will not buy them, will you? You can choose the fresh ones, leaving the losses to the business that sells rotten fruit (it's their responsibility to control their stock).
Now, let's say you buy your grocery online and get it delivered to your home. Do you expect rotten fruit? Is it acceptable? If the company tells you "oh, but we don't have a warranty on fruit unfortunately, we don't guarantee that they will last 30 days". It's still not acceptable, you will refuse the delivery and get it back to the sender. You will also lose confidence on that service, and go buy the fruits yourselves on the shelves, where you can observe if they are fresh or not.
That's the same thing with those Nest Protect devices. They go bad after some time, and it's OK. They have a limited 2 years warranty after the purchase, and that's OK. But that's not OK to sell 200$ devices full price to customers that can't know in advance if the device will last them 9-10 years, or last them 4-5 years, because the employee that picks them off the shelves chose any one.
Now I'll go at Wallmart or Bestbuy and pick one that'll last 9 years, for the same price.
