What is interesting though is that (some) keyboards are so easily reprogrammed now, why wouldn't we all just have our own personal layouts? (Obvious reasons considered later.)
Switching to a staggered column (rather than staggered row) layout is taking some time to get used to, and being on a split keyboard is also quite new. I really do get that slight changes (maybe just for me), take some getting used to. But even give that I'm a complete convert to heavily revised keyboard functionality. Which I say as someone who could easily switch their layout at the literal press of a button - this keyboard has both dvorak and colemak layouts on layers).
I have shift keys on F and J (hold down to shift, tap to get the letter), another shift on one of my space bars (i have two), an escape key under my thumb (which is also right control), and a couple more magic keys. I like some, some are taking getting used to.
I get 40% keyboards now, and how people get used to them (no, this isn't a 40% it's an ergodox). I could imagine moving to a small keyboard at some point (I have a 30% kit due any day, but I mostly want to use that to practice soldering).
The thing I get is adding extra functionality. One one layer of my keyboard I have some often used shell commands (i.e. - two key presses gives me '| grep -i ' which I end up typing more than you would imagine). The shift keys thing, is actually nice and useful, i have a key on my 'normal' layer that is a copy, and one that is paste (and on another layer one key does copy, alt/tab, paste - which again I do moe often than you'd imagine). Once I'm fully comfortable with keyboard, then I think I'll likely add many layers.
I suspect it's quite normal, but within a week of getting the ergodox I had gone through 22 significant layout changes. My layout is fairly stable now, but I suspect within a week I'll have decided to do some more clean up (I'm not entirely happy with my backspace and enter situation, and I rarely use ; but often use : - so why do I even have a key that's usual output is : rather than : ?).
So why wouldn't we all have personalised keyboard layouts? Obviously on your own keyboard it's fine, you could just take that with you and use it, but logging in to a hotdesk machine with a standard keyboard is fairly normal, and you wouldn't want that normal keyboard to be mine... Some of this could be covered by having a new standard of keyboards sending basic codes and all operating systems translating those based on user profile (people on windows often have auto hotkey macros which I assume are a version of this), but even that, which I suspect is unlikely to ever happen no matter whether it's even a good idea, wouldn't cover when you are at someones desk, and need to use their keyboard for something (working together on a document, for example).
I this where really an issue it would actually not be a hard one to solve, I suspect. Have your keyboard profile on your phone and tap it to a keyboard to switch profile (hmm, nothing nefarious could happen with that...) But really It's not a problem, and it's not a problem because most people just are never interested enough to actually want to reprogram their keyboard. No matter whether I think it's something I would not want to do without in future, it's a terribly niche requirement, which I think is as pity, but I'll not lose sleep over it.