I'm typing on my 2015 MBP right now! It's not as good as a blue-switch or Alps mechanical keyboard, but it's pretty damn good!
Just looking around though, I can see that the majority of external-keyboard users here in the office are using 2016-and-later 4th gen MBPs. The keyboard is just bad enough to mandate rather than encourage external keyboard use.
I think I actually type faster on my MBP, but I get more enjoyment out of a mechanical keyboard.
It could be argued that a MBP is the wrong tool for the job then and they would be better served with a Linux-powered laptop.
> We’re a company of super-efficient touch typists, and the 2015 MacBook pros with their scissor switches are coveted and traded.
If you want a REALLY good keyboard nothing beats the old ThinkPads before they went chiclet. Those would be even more coveted.