I think you're selling some of these companies short -- the thing they might seem focused on now was not the thing they initially got popular for doing. In other words, they innovated outside their expertise to stay relevant.
I don't see who the loser is in this story. It isn't Cisco shareholders; they can be Zoom shareholders too if they want to be.
Sure Cisco shareholders would have been better off if Zoom was an in-house project, but investors are really the ones who are supposed to be making the value calls on teleconference-or-routers market exposure style decisions. If I'm a Cisco shareholder I don't think management made a mistake. I think I made a mistake not becoming a Zoom shareholder.
I want them to fire the management chain that was involved in the zoom debacle, and also fire the people that hired / promoted that management chain.