Thanks for the detailed sources, it’s nice to see people were discussing keyboard layouts in 1990 
I disagree with them never being ‘much good’ for using without looking. The distinct grouping of 1 - 4 - 4 - 4 - 3 buttons that are 1u with a backspace acting as an ‘end of function row’-locator make them easy to distinguish even blindfolded. I can quite literally hit any F key without looking if they are grouped in this way (and have a non-zero spacing vertically, the model M spacing is quite large).
Well I do agree that in general user interfaces should try to fit their shortcuts in the modifier+alphanumeric range, IDEs like IntelliJ (which is the primary IDE at my workplace) simply have so many shortcuts that you quickly run into physical limitations with finger location.
Let’s say you want to copy a file in IntelliJ. The default shortcut is F5 (Windows and Mac). Here Fn+5 would work very nicely assuming Fn is placed appropriately.
Now you instead want to show usages of a class in the codebase. The default shortcut is Ctrl+Alt+F7. Left pinky and thumb go to Ctrl and Alt. The right hand needs to press Fn and 7 meaning you have to move it away from the home row and voila, you now have a slightly more shitty experience compared to just having the damn function key row.
That example may be a little contrived but there are a number of very useful shortcuts in IntelliJ (VS and VSCode too) that require 1/2 modifiers + function key. Is this the right way to make shortcuts? Maybe not if you assume people roll in with 60% boards. Was it a reasonable choice given that IntelliJ was released in 2001? Very reasonable indeed 