Because people are morons when it comes to actual RAM usage. There is no need for a well managed phone to use 4+ GB of RAM. I agree 1GB is starting to be a bit long in the tooth, but having multiple gigs in 2013 is ridiculous on a phone.
Exactly what usage pattern are you guys having that is causing RAM issues? I ask, because I never run into any problems. I've heard silly things like "when I have multiple tabs open in Safari and then try to view them with no network connection, I can't because they are stored in RAM forever." Wtf? Why on Earth are you consistently without any network connection?
When I have multiple Safari tabs open, the tabs may reload when you switch back and forth between them. (Yes, this happens when you're still connected to the network.) This drives me up the wall in certain situations... which just happened on my phone just now... like when you're making a post and then decide to switch to another tab to check something out or to copy a quote, and then switch back again. If the tab you were making your post in reloads, then suddenly you've lost everything in that post and have to start over. This is really, really aggravating, and happens much less often on the iPad Air 2 which has 2 GB RAM.
One potential way around this in the future on my iPad Air 2 would be to use Split View in iOS 9. That keeps both screens side-by-side and active. The main problem with this is that Split View currently doesn't allow two instances of Safari to be running at the same time. However, hopefully that will be supported in the future, or perhaps you can run two different browsers in the future side-by-side. But at least right now you can run stuff like Mail and Safari or Notes and Safari at the same time. And guess what? Only iOS devices with 2 GB RAM support this feature... which means only one device, which is the iPad Air 2.
Just like I refused to buy the original iPad with 256 MB RAM, I refused to buy the iPad Air with 1 GB RAM. I'm sooooooooooooooooooooooooo glad I did in both instances, because I tend to keep my iPads a long time. Or maybe I keep my iPads a long time because I can, because I made the correct hardware choices at the time of purchase. Just like for computers, RAM is very important iOS devices.
BTW, Slide Over in iOS 9 is kind of annoying. Yes you can slide over another app over your currently running app, but it's almost the same non-multitasking of previous generations because it greys out your running app. This is what the 1 GB iPads get. Unfortunately, as you might guess from my description, it's not anywhere near as nice as Split View, and as mentioned, it's not true multitasking.