Wait how do zombies eat time, exactly? If they have cash flow and are viable businesses, what do they need from the VCs that would take up their time?
I mean, yes, obviously, it's rude and unpleasant to say "I don't have time for you because you're not making enough money," but it's a lot more unpleasant to say "I'm firing you and all your employees even though you're making a profit because you keep asking for favors and it's annoying."
2) If you cut ties with entrepreneur A cuz you think his company is zombie, he doesn't tell you about entrepreneur B who is about to start the next big thing
3) i.e. it's like high school. You want to always be in the right crowd invited to the right parties. And if you stop associating with a certain group of people, you better be sure those are not the future kings.