And furthermore, with the exception of Safari tabs, and maybe a few choice applications, 2GB of RAM would rarely be beneficial. At the end of the day, you would only be more prone to killing "running" apps that you open once and don't plan on using again the majority of the time, because they actually WOULD be using a significant amount of memory. As it stands, the majority of the apps that I close, I do not plan on reopening.
As I have said, with the exception of Safari and maybe a few other apps that I briefly exit, only to find that upon return they need to be reloaded, 2GB of RAM is very unnecessary, especially considering how efficient iOS tries to be with its resource usage / power consumption, and how the majority of the apps that are using a significant amount of RAM would most likely never be reopened (Im talking briefly opening your email app to check for updates, and after realizing there arent any, you close the app, but it stays in memory for significant amounts of time afterwards).
That being said, I am not trying to justify only 1GB of RAM, but I do understand from Apple's perspective why they did not choose to go for 2GB. Also, I would bet that the MAJORITY of users would NOT benefit from 2GB or RAM the MAJORITY of the time.