The world is far too big for anyone to care as to a minute detail of "Developer John Doe didn't meet my productivity metrics". That's worthy of a (mental) eye roll. Workers in this industry, at the moment, have the leverage, not the employers.
95% of the time someone attempts to bury or denigrate the reputation of another professional like that, it does more to damage their own reputation. The issue at hand is almost always as you quoted something relatively small and meaningless or at least related to context completely unknown to the audience. It only serves to advertise "I think I am bigly enough to talk crap about my former subordinates, so you should be very careful about working with me."
True but the tech world IS small. I’m not coming to the defense of the business or management but there is some truth to it. Everyone is only a degree or two from anyone else in the BA, and you bet your ass people ping old coworkers about candidates that land on someone’s desk.
You may eyeroll but if you have a trusted coworker ping someone and they come back with “he was the most unsuccessful junior dev I’ve ever met” (a real personal story) that guy does and did end up at the bottom of a waste basket
But there's a big difference between a system where you are unhireable once you disappoint someone, versus just living with a risk that someone where you apply might know your last boss personally.
I can't think of any case where someone left a job in tech for any reason (fired for cause for getting in a fight, bridge-burning angry walkout, etc.) and didn't emerge someone else better off. I've always assumed it was because hopping around just pays off, no matter the reason, while sticking around (especially when it's not working out) tends to be bad for your career.
