Your mum's so FAT32...
Real doctors take an oath to do no harm with the knowledge they've been granted. I guess that's why the CIA went with psychologists.
I don't think the principle is meant as a critique so much as a statement of a regrettable tendency in the way that things in employment situations simply are.
Yes, in practice it's usually a mix of the two, so the principle is more an abstract model than an argument about real, concrete thresholding.
But the general idea is that by the time someone stops being promoted, if they continue in the job that they are in while not being promoted for an extended period of time, it means that they are likely not amongst the highest-merit individuals around for that particular job and responsibility list—because if they were, they'd have been promoted and/or would have moved to another job elsewhere that offered an equivalent to a promotion.
The best way to understand the principle is to imagine the counterfactual.
When does a person *not* get promoted any longer? When they are not actually that great at the position into which they have most recently been promoted. At that point, they do not demonstrate enough merit to earn the next obvious promotion.
So, the cadence goes:
Demonstrates mastery of title A, promoted to title B.
Demonstrates mastery of title B, promoted to title C.
Demonstrates mastery of title C, promoted to title D.
Does not manage to demonstrate mastery of D = is not promoted and stays at that level indefinitely as "merely adequate" or "maybe next year" or "still has a lot to learn."
That's the principle in a nutshell—when you're actually good at your job, you get promoted out of it. When you're average at your job, you stay there for a long time.
Find a word that fills that blank and really focus IBM on being that company. The agile process won't fix bad leadership at the top. The agile process never fixes bad leadership at the top.
Old programmers never die, they just hit account block limit.