I've said it before and I'll say it again.
Big or small, they'll tell you they are family.
And they are. Like a Mafia family. They demand loyalty and obedience above your personal life.
Company (Mafia Family) comes first.
Then only to fire you / lay you off at a hint of a downturn. Oh you got whacked / laid off? It's just business.
Edit: And reasons are the same – Profit & Greed.