Incorrect! I have worked on a high quality, wooden card table for fifteen years as a professional programmer. I am right-handed and there is no way there is room for a mouse or (as I actually use) a trackpad with a number pad on the keyboard.

I've tried a couple of numberless keyboards and those crowd my mouse area. I am firmly and permanently settled on the Apple keyboard. It is tiny, silent and perfectly reliable.

(In a bizarre side note, I left one out in the rain the other day, a downpour. It still worked.)

Fair enough, I phrased my statement too strongly. Let me restate: I have never ever in my entire life seen a desk which was so small that shaving a few inches off a keyboard would actually be significant. And mind you, that includes shitty call center desks which are built to be just wide enough to cram a computer station in. While it is possible they exist, the fact that I've never encountered even one causes me to doubt that most people who say "my desk is too small" actually have a desk which is too small for a 100% keyboard.

For some of us, the sideways reach / horizontal flexion for the mouse (thumb trackball, in my case) can cause wrist or arm pain.

It's not about desk space, it's about ergonomics.

I switched from a 100% layout to a 34-key keyboard last year. It's not about the desk space at all, it's about never having to move my hands while typing. E.g. instead of reaching for the arrow keys I use a vim navigation layer. Instead of reaching for the number keys -- or, even worse, a numpad way off to the side -- I use a numpad layer. And mod-taps are amazing.

The small size is nice for portability -- my keyboard is split and wireless, so I can easily stick it in my backpack and set it in front of my laptop on a table anywhere. But again, the main benefit of a compact layout for me is ergonomics rather than size.

It's often said that but I don't agree that removing keys (especially for F1-12 row) is for ergonomics. You can remap F keys to combination even if the keyboard has dedicated F keys. I do that because dedicated keys are sometimes useful for me and I don't care additional spaces by adding a top row. Removing it is for cost saving and portability.