Many people in general and even here will and do put app loading times, switching between apps, and other things of that nature under the performance category. If you see many complaints they mention quite a few of those things. Sure, things like animation stutter might be less relevant to that, and while many complain about those as well, performance goes well beyond that for most.
Well it depends what kind of app loading. It's just a matter of fact that a modern app such as Facebook will load longer on older devices. No conspiracy, no greedy Apple, just the truth about technology and this thing called progress.
Obviously if iMessage suddenly needs 2 times to load than before than yeah that does suck. But even that sort of makes sense with how software works. Just because you cannot see a visual change doesn't not mean nothing has changed.
Most complaints I have seen is about app delay, animation speed, stutter, slow reponse, animation priority etc. There is not a lot of threads, at least not anymore, of how things don't stay in memory. It's all about raw iOS performance, smoothness and responsiveness is the magic word that people use a lot.
I just find the conspiracy theories hilarious. I'm sure at one point you will have to make trade offs where you add new features, core functionality to an OS which than will in turn affect older devices.
If Apple made a version of iOS each year that runs exactly the same on all devices as the previous version, without ZERO tradeoffs, they would never progress. Half the stuff they added just in the last 2-3 years you probably would not have. But hey at least iOS would run smooth on those s***y iPhone 4s.
Get a life and a 5s.
