Sorry but that's BS. Really old, every time a similar question is asked, there comes a guy like you saying that it's all about the money. Apple would have more things to add on the iPhone 6S to make it upgradable from the iPhone 5s and they are not going to mention the RAM increase on the keynote anyway. Changing the RAM capacity on their devices every year or so is not what Apple does. Apple does have a different philosophy then other mobile phone manufactures. While others focus on spec sheets, Apple focus on the user experience. I have said this before and I will say it again: What difference does a higher RAM capacity makes if the user experience on your device sucks?
Oh, by the way.... how many 4 year old devices from other smartphone manufactures you see in the wild? Because I see lots and lot's of iPhone 4 and 4s users.