It sucks but IMO the memory line of argument is probably the weakest in this whole discussion.
It seems however though, and this is an assumption I can only base on personal experience of what I see, that people like all the 'stuff' during their work that eats battery and memory and cycles.
All the animations and things that go on in the popular wms and OSs and browsers that deliver no 'direct value' to me (like said; this is I personal thing I believe) seem a must for most people even though they are devving.
Why would one use the incredibly heavy and animated WMs over something fast and simple which even works faster (for me!). When I use Unity (latest) my laptop has 5 hrs battery; switch to i3 and plop 10+ hours more.
Do people like that so much or am I just completely wrong?
(one other reason I see with colleagues is very heavy IDEs but let us not go onto that)
For example, I'm working on a Macbook, but inside a Linux VM. It was running at 3-4 GB RAM for a long time, but I had to bump it up to 6 GB when I was working on an interconnected set of Rails applications. (Ruby and Rails are notoriously memory-inefficient.)
Another example: In 2010, I had to upgrade my notebook from 1 GB to 2 GB of RAM, not because of KDE 4 (which was considered absurdly resource-intensive at the time), but because of Git. (Git is designed to use the filesystem cache extensively, and will become absurdly slow when the cache is too small.)
I was responding to many people who 'cannot work' because they have less than 16gb, the latest discrete gpu and cpu. Which is where all the mb pro whining now revolves around. You are playing to 'if you have more you spend more?' human condition right? If you have more money, memory, speed whatever, you will find some way to use it fully; that is true. But you do not /need it/. I was the same a few years ago until I dropped Mac OS in favor of Debian and bought a stack of old (2011) laptops. After tweaking everything but the stuff I do not need on it, it works as well /for te dev I need it for/ as the last (2015) MB pro I touched for a fraction of the price and i3 does make me more productive.
Anyway; I am not trying to convince or sway anyone, just saying that, imho, it is nonsense that most (by very far margins) really need that kind of metal. But sure, if you can get them, then get them. In my slightly older age I try to get back to simpler and more optimal. The cyclewaste/bitwaste is getting annoying to me (IF it is waste; I do deep learning and play/fiddle with games on heavy metal).