From the above example, it's clear they are offering the extended warranty because it works out better to have more warranty returns but they can make more with the extra services and have a better looking selling point at the same time. Let me guess, you can only get it serviced by them?
I don't think the extra warranty has anything to do with how much more confident they are in their product. In the end, if you want your extra long warranty, you are actually paying extra to have it.