Zoe Schiffer, writing for The Verge, investigates Apple employees and « the blurring of personal and work accounts. »
This is how it starts: a new Apple employee is told during onboarding that collaborating with their colleagues will require them to make extensive use of iCloud storage, and their manager offers a two terabyte upgrade. This will link their personal Apple ID to their work account — in fact, the instructions for accessing this upgrade explicitly say “you must link your personal Apple ID with your AppleConnect work account.”
Check It Out: Examining Apple’s Carefree Attitude Towards Employee Privacy
Sounds like a perfectly good reason for two icloud accounts.