I suspect it has something to do with their typing habits and/or some physical issue.
Personally, the newest Macbooks became a problem for me despite the history of amazing palm rejection on Macbooks, I have sort of sweaty hands and when they increased the trackpad size, that combined with how I type (palm resting on the chassis, not raised), it causes a lot of jitter (I say a lot, it's super rare, but just enough to train me away from it) and I've ended up using an external mouse exclusively, but in the past year, uh, I haven't been mobile so that's just a nonissue :)
Personally, the newest Macbooks became a problem for me despite the history of amazing palm rejection on Macbooks, I have sort of sweaty hands and when they increased the trackpad size, that combined with how I type (palm resting on the chassis, not raised), it causes a lot of jitter (I say a lot, it's super rare, but just enough to train me away from it) and I've ended up using an external mouse exclusively, but in the past year, uh, I haven't been mobile so that's just a nonissue :)