This has nothing to do with the Android operating system. It is the fault of the OEM and Carriers for not updating the devices. The idea is that your device will malfunction and you will buy a new one. This is how they make money. My best advice is, as @chuckh1958 suggested, to buy a device that is supported by CM or other custom ROMs. That way you can perform your own upgrade and stay current with security patches. Think about it. If we each only bought 1 phone every ten years.... there would be a lot of panic in the CEO department. I have a Galaxy SII and I am currently running MARSHMALLOW v6. 0. Official support ended at 4.2. Also altering your kindle might be an excellent idea. Once again the longest lasting, best supported device on the market? Google Nexus! Don't blame them, blame your carrier.