[ye-olde-sysrq]

Part of it specifically unique to software and is because companies are terrified of getting a bad name since it'll make hiring so much harder. Lots of companies have average tenures of 2-3 years so if you're not constantly hiring like 30% of your current headcount each year, you're going to be shrinking.

(I could rant about how it didn't need to be this way and that between noncompetes, nonsolicits, aggressive perf processes, and giving shitty raises the turnover is entirely their own fault and everyone would be happier job hopping less. But that's a rant for another time.)