First, let me say that while you obviously have a bias towards less RAM, it's is kind of refreshing in an age where in many threads, people suggest throwing 32GB, 64GB, even 128GB of RAM at everything... so moderation is a nice perspective. But like I said, I think you're pushing it way too far.
Have you installed Mavericks? Would you mind posting a screenshot of your memory pressure? (under mavericks)
He no longer has it (got a new MBA before Mavericks came out). But even Mavericks will suffer slowdowns with 2GB in typical usage. You're implication that Mavericks would have fixed it is wishful thinking. Just because Mavericks lists the system requirements as 2GB doesn't mean it will operate efficiently with that little RAM.
Software has demanded more and more because developers programmed it that way...
all system requirements change. By the time ram requirements have changed cpu, gpu, storage, wifi,... requirements will have changed as well. What makes ram so special?
So your solution is to get less RAM on principle to force software developers to be more efficient with their programming? That doest seem very practical.
This is a RAM discussion, so that's what I was addressing, but I would address other components like CPU in a similar manner. However, RAM
is different. With a CPU, everything gradually gets a little slower year by year, or the user has new software needs, and the computer is slower to perform compared to a faster one. However, once you hit the RAM bottleneck, you're left looking at colorful spinning beach balls. Those get really annoying really fast.
why would this not be something a normal user should consider?
Sorry, I thought it was implied in my answer, but I can see now that I was vague... having more RAM does not appreciably affect battery life.
BTW, memory compression isn't "free" either - the CPU ramps up to perform the compression, which uses more battery. While that is better than being forced to use swap, simply having more RAM is the most efficient.
if a app runs in the background then it likely uses power. People tend to forget to close these apps unless they are reminded/forced by their systems slowing down. This takes away some of your freedom as a user but it will eventually let you appreciate your macbook more. The battery life is one of the big charms of

devices.
If you're offering tips to save battery life, that might be good advice
depending on the situation. Simply having more RAM is really the best approach. Apps idling in the background generally don't usually have much of an energy impact, but that's where Mavericks new "Energy" tab (in Activity Monitor) is useful.
You seem to have an unusual approach to this that it's somehow "good for you" to do with less RAM.
No offense, but the
"This takes away some of your freedom as a user but it will eventually let you appreciate your macbook more" line should be in the annals of the Apple Fanboy Hall of Fame.
Anyway, you're entitled to your take on the RAM, but in other threads you've been encouraging users to come visit this thread for RAM advice, and I wanted to suggest to your readers that your guide is biased to a certain viewpoint.
My viewpoint is that RAM generally comes down to budget, and most users who skimp on RAM will regret it down the road. 4GB is too little for a new computer that most users expect will last them at least several years.
Cheers!