Earlier quoted context omitted.
Most are horrible. One of the reasons is overlap. Your hands do occasionally hit keys on the other side. You want a pair of 2/3 keyboards, rather than 1/2 keyboards. You /especially/ want a lot of the "special" keys on both sides. Another is key action. You want proper mechanical keys. A third is mounting. That's a problem which hasn't really been figured out. The middle hinge or fixed setup is definitely sub-ideal.…
>One of the reasons is overlap. Your hands do occasionally hit keys on the other side. When I switched to a split keyboard I did have this problem at first (with the B and 6 keys in particular on a QWERTY layout) but it took me a week to relearn that. In particular if you use an ortholinear layout on each side there's really no reason to go fishing for keys with the wrong hand. This in turn means that you can add new…
If I give up a few things I like about my existing keyboard to get what you like about your keyboard, that's a bad deal. I think that's true for most people.
The type of mechanical keys on my keyboards really reduce the amount of strain on my wrist relative to membrane keyboards. It's not just a matter of taste. There's much less of a bump on the bottom if the key can continue moving after the keystroke is triggered. Membrane keyboards can do a little bit of that, but not nearly as well.
Trackpoint, implemented well, means I can do casual mousing (e.g. switching focus) without moving my hands to the mouse. That reduces shoulder strain.
You're welcome to call things I like "a bad idea," and I could do the reverse just as well, but at the end of the day, I ain't buying. I know what works for me, and I haven't found an "ergo" keyboard which does.