[luismedel]

I think it's only a matter of sales strategy instead of a technical one.

They (be Google, Apple or whoever makes OS and/or phones) have the know-how and the tech to support older devices for a longer time. Even if they limit that support to only publish security updates for older systems (which, IMHO, I think it's the correct thing to do). Come on, see the Windows XP latest updates.

A phone it's not different. In it's core, It's a f computer running software. The main difference is that the average Joe is accustomed to replace them even quicker than desktop/laptops.

Apple et al are fixing the "errors" they made with the personal computer market: support them for a long period of time, or giving the devices a longer (and secure) life via security updates, so your sales plummet.