Regardless of it being a RAM issue or not it's still an issue.
At this point I don't understand why Apple won't fix it.
It's annoying, it uses MUCH more data (relatively speaking), it waste time, it waste battery, you lose information previously input, etc etc.
With iOS 6 I never noticed this. With iOS 7 I'd have to make it happen. With iOS 8 I notice it constantly when using Safari.
Well there you go 😉 One of your reasons this feature doesn't get changed. Don't forget the whole design of the device was based around cloud based apps etc, always got the latest and most current version etc...