[kpil]

I think that in reality most companies (up to a certain size) or projects have people that are pivotal, enablers or highly influential. Not only charismatic leaders but also technical wizards, etc.

They might not be irreplaceable but they might be hard to replace, and if they leave in the wrong moment, it could jeopardise everything.

I guess having a management team made up of several Steve Jobs might arguably feel safer for the share holders, but it's probably hard to find them and make it work.

There are risks to manage; For instance, treat them nice so whole teams won't quit in rage. Treat the unicorns even nicer.