Because they're talking about USB keyboards they're probably talking about the chicklet Apple "Pro" USB keyboard, not the new MBP's built in keyboard. Which, I agree-- I've only typed on the actual laptop itself a handful of times, but man, those key movements are SHORT and I'm not sure I really like it. Time will tell, though -- I originally felt the same way about the chicklet keyboards i love now.
Now, my wrists also hurt. Now, when I'm not travelling, I was using an external Apple keyboard, not the MBP's primarily, so I'm hesitant to blame the MBP's keyboard directly. The external Apple keyboard has a greater keystroke distance from start to bottoming out, but still has like zero distance between actuation and bottoming out. (For some keystrokes, particularly ^+Tab and ^+Shift+Tab, I find it hard to keep control actuated, despite it being fully depressed; it just seems to require a lot of pressure to keep things in electrical contact). The pain in my wrists didn't start until I started using Apple keyboards, and has mostly stopped since I've replaced them. (I now primarily use an ErgoDox EZ, primarily for the split/ability to independently position my hands. I had tried, and had similar success w/ a Kinesis Freestyle, but I didn't own it.)
(I used a MBP keyboard for ~4yrs, with an ergo keyboard of some kind for when I'm not travelling for ~half of that. I've used Thinkpad's of varying models for ~10 years. Now, I could just be getting old, but replacing the Apple keyboard is what made the difference thus far for me. It doesn't make a lot of sense to me, admittedly: my wrists are, I feel, in the same bad position on the Lenovo as they are on the MBP/Apple keyboard.)