I know you are right with everything you have written. However you are seeing thing just through your eyes. If the world consisted only of Sebbbis (and equally proficient developers), 4GB would probably be enough for a long time. The truth is however, for every Sebbbi there are 25+ Joe Average programmers. Don't get me wrong, most of them are hard-working and dedicated people, but will never-ever reach your level. Having 16 GB will help them get similar performance (and frame consistency) you can achieve with 4 GB.... a lot of intelligent and insightful things.
When you look at the IT industry today there are a lot of people who would have struggled to make a living from software development 25 years ago. Having lots of CPU power and memory to waste means can afford to be inefficient. There are people out there who use Node and dozens of JavaScript packages in order to write software that effectively consists of 100 lines of code. It's a terrible waste, but everybody has come to accept it outside of certain areas, because it enabled people to do stuff they could not have done with IT technology 25 years ago. GPU will go the same way sooner or later.
I really admire your skill, but not everybody can be like you.