In a way, they did. Because they had to. They did not have octacores and 16GB RAM so they had to optimize. Jolla with 1GB struggles to cope with keeping more than 3 apps open, something that N900 does effortlessly with a quarter of that.

In terms of screen resolution, I appreciate that my post was a bit long, but please try to understand that I am not against a high resolution per se, only against poor optimization. Unfortunately, as is the case with pretty much everything in life, more resources are often interpreted as no need to optimize.

But that is exactly the point! Howe much you can comfortably fit into the screen is not a function of the screen resolution, but the screen size. If you cram more things onto the same 4" screen only because the higher resolution allows you to, you will end up with an unusable interface.

Now turn it around. If you cannot squeeze more things into the screen despite having a higher resolution, then what is the point of the higher resolution?

Actually, what I would advocate is a constant pixel density, independent of the screen size.