If Apple doesn't let its apps get more intricated, competitors will do it first...
Plus developers have got the increased power of the 64-bit A7 and the features of the M7 chip to keep themselves entertained so it's not as if Apple are treading water.
Besides do we really want to recreate the "requires a minimum of X Gb RAM to run" small print world of Windows games?
Also, Apple has the power to mandate that all apps have to run well on whatever old hardware Apple wants to keep supported. There's no good excuse.
Apples approach to extending background services was to engineer a 'motion coprocessor' to handle one class of background tasks as efficiently as possible. Samsung et al just saw the memory utilisation on their devices go up from the services they're running so they jacked up the installed memory.
The second consideration is battery life. Memory uses battery power all the time, whether that memory is doing anything useful or not. Apple is fanatical about power conservation. You don't get 10 hour battery life as a standard feature on your mobile devices by accident.
So yes Android will use more memory if there is some available but there's no evidence to suggest it needs more than iOS.
BTW, there's another class of software Android devices run that consume more RAM. UI widgets. Now that's perfectly legitimate. If you like widgets, Android or WP are the way to go. It's just that they have a cost in RAM utilization, and therefore device memory specs and power consumption. If Apple supported UI widgets, they'd have to also increase memory capacity to maintain system performance and stability, so they don't. This is an area where reasonable people can have a difference of opinion. Apple prioritize battery life and lean system design, Android emphasizes features and customization.
No. I am talking relative here. Relative to my iPad my 1GB Android devices ( N7 (2012) and GNex) reloaded browser pages or lost background audio/video playback noticeably lesser. However on my Note 2 which has 2GB RAM, I very rarely see browser page reloads and don't remember having lost background audio for example at all (something that happens routinely on iPad and sometimes on the N7.)
So what I am saying is that Android devices don't _need_ more than 1GB - anecdotally they offer slightly better multitasking performance for the same 1GB than the iPad. But both on Android and iOS - the experience will get appreciably better with 2GB RAM given how smoother my Note 2 is and given how many times my iPad reloads/loses stuff. (Just check the diagnostics logs for low memory on iOS devices.)