If those are the only factors and the numbers fall in particular ranges, sure. Otherwise, no.

Try doing the math here. How much cheaper would a netbook get if every single developer coordinated to reduce RAM and CPU usage? $5? Maybe $10? Looking at market prices, old RAM and CPUs are cheap. They consume basically the same physical resources as new RAM and CPUs, so price competition for not-the-best hardware is fierce.

Now ask those people if they'd pay $5 or $10 more for assorted new software features. Any features they can think of. And keep in mind that in that price range, people are paying $10 more to pick the color of their computer.

So sure, it offends me a little, because I like optimizing the things I pay attention to, like RAM usage. But if instead I optimize for the sorts of the things users care about, especially as reflected by what they'll actually pay for it becomes pretty clear: users don't care about the things I do.

So then the moral question becomes for me: who am I to impose my aesthetic choices on the people I'm trying to serve?

Eink displays only use however much the battery inherently loses when not changing pages. If you only read 500 screen of text that month then it only consumed a trickle of battery x 500. Your screen itself consumes power every second its on and you also ask much more than rendering text.

What you propose is interesting though none the less. What is the most battery life that can reasonably be packed into a device that is modest but still useful.

Sure, but that won't come from people programming differently. The laptop backlight alone is a few watts. If your battery is 40 watt-hours, you're not going to get to 2 weeks of usage no matter how little the CPU gets used.