This is an issue with big banks like Capital One. The management culture is absolutely awful there and they hold a tremendous amount of power and of course abuse that power as well as abuse the workers.
I've also not seen anybody leave the company on bad terms. Of course I'm sure that happens, and I'm sure there are bad managers here as everywhere. I'm sorry that you had such a negative experience.
I used to work for Capital One Europe, the UK side of the business that currently only does credit cards, until last year. I'd seen a mixture of some people leaving on good terms and some on bad terms, with no obvious correlation to performance. Personally, I left on good terms for a new role elsewhere.
I'd suggest when you're talking about a company of sufficient size; there are always going to be a mixture of those leaving on good terms and those not.
I get yelled at on a weekly basis. Belittling is comon too, such as being told "you're not that smart and this isn't rocket science". Managers are non technical managing a technical project and micromanagement is the norm.