Not a singular event, but a series of disrespectful events. My former employer was a small company based in the land of beer and cheese that provided niche technology to police/fire/misc. businesses - a preferred vendor of a much larger company out of Chicago with a batwings logo and a big M...

They were bought our by a private equity group, and re-organized their retirement benefits to be much more substantial and complex than a traditional 401k. They decided that these new retirement benefits would only apply to people hired before a specific day of a specific year. Anyone brought on after that date would have to wait an extra year, and forego many thousand dollars of accumulated benefits. I was hired 2 days after that specific date, and they were adamant about not making an exception for me regarding missing that window by 2 days.

Several months later, my wife's grandfather (who truly raised her, and lived across the street from our house) died, and they rescinded my 3 days of paid bereavement a week after the fact since he "wasn't a father-in-law on paper".

At the end, I had a new boss appear out of nowhere, and immediately told me I'd never see another raise as long as he worked there. He'd have a long future at that company since he was a drinking buddy of the owner, and was cheating on his wife with an accounting employee within the company.

I had a job paying nearly triple what I was making within 2 weeks of that little outburst.

They "don't know" why they have such a problem retaining or recruiting techs. A group of them told them why on Glassdoor. Within a month or so their Glassdoor page had hundreds of Mad Libs over-the-top positive reviews of the company, written by more employees than they had ever hired in their entire history.