That’s a valid reason to choose a repaint rate, sure, but 40Hz? It’s halfway between 30Hz and 60Hz (yes, it is) but it seems like a poor choice, to me. 60Hz would have been much more reasonable.
Also, why do userland applications need to know the monitor refresh rate at all? Repaint when the OS asks you to. Linux is a huge pile of crap pretending to be a comprehensive OS.
Yes, you're right, you're absolutely the smartest person in the industry, and absolutely everyone else doing all of this work has no clue what they are doing at all, and should absolutely bow down to your superior intellect.
You not understanding why something was done, much with your orignal comments about 40hz, doesn't actually mean that it is wrong, or stupid. It means that you should probably spend time learning why before making proclamations.
Also, why do userland applications need to know the monitor refresh rate at all? Repaint when the OS asks you to. Linux is a huge pile of crap pretending to be a comprehensive OS.