Not increasing the RAM is like retroactively future proofing previous devices. As noted, updates (OS and apps) degrade quickly on devices with less memory once newer devices that have more come out. Don't get me wrong, I'd love to have a 2GB device, but I have little doubt that 1GB devices would be rendered half useless by memory hungry updates within six months if that were the case. Software abhors a vacuum.

True but considering iOS 8 works right back to the 4S I wouldn't be too worried. Plus most people are on two year contracts and upgrade after that.

I'd have to really wonder how well it runs on the 4S. People have gotten burned in the past, downloading the latest iOS for their phones that Apple advertised as technically being able to be updated, but really didn't work out well in practice. IIRC the iOS3->iOS4 upgrade was like that.