Fixed-distribution stack ranking is bad for precisely the reason pointed out -- because of differences between team missions, personnel, and capabilities, the values are basically scale-free when compared across an organization. It also means that employees, particularly at the upper management level, are graded relative to factors that are exogenous to their performance (if you do a great job running a declining or static business unit, you're likely to take a hit relative to an executive doing a worse job in a better sector).
Rank-and-yank arguably worked well at GE because Welch was dealing with a large, unwieldy, and poor-performing conglomerate that had a lot of room for workforce reduction. But as the company got leaner and more effective, it got rid of the practice, and it's unclear why tech companies -- which one assumes haven't had time to get lazy and complacent -- jumped on the bandwagon.
In fact, theoretically, if you're constantly cutting the bottom 10-20% of performers, and the quality distribution of new hires remains constant, at some point you should have pulled up the overall quality of the organization. The fact that you can't create a perfect organization by constantly cutting the lowest quantiles suggests that either something's wrong with the ranking systems used (which there is!), or that the practice has deleterious effects on retention, behavior, and morale (which it does!).
Practically, this means that, as a manager, you get really good at piling up deadwood until the order comes down to swing the axe -- far easier to keep a few window-seat employees around to satisfy the Layoff Gods than to go to war every time you do your QPRs. You might also coordinate with lateral colleagues to move good employees around so you can keep them in the game.