The "it works for most people so we won't bother acknowledging or fixing it" defense is indeed Apple's position on this, but when you have a significant number

The "it works for most people so we won't bother acknowledging or fixing it" defense is indeed Apple's position on this, but when you have a significant number of people experiencing this for multiple years (at least 5) on multiple OS versions on a multi-thousand dollar machine, it brings to question the quality of said machine. The problem is so bad, there's software out there to compensate for it (http://smoothmouse.com/ http://smoothmouse.com/) which obviously is a band aid that only works for some. So no, it's not a defensible position as it renders the $3000 machine useless, similarly to how a $3000 car whose steering wheel steers randomly would render it useless.