Mark Cuban says Silicon Valley today is like the old Hollywood. Everybody wants to be an actor, everybody wants to be an entrepreneur. Your employees are there only until they can take a chance to go start something news, or go somewhere else with a better potential return.
There is a lot of money and investors are just throwing that money at potential companies, in hopes of a good return. This leads to a lot of bad habits and bad culture.
In Mark's view, almost any successful company that had started in recent past would be more successful by being based outside of Silicon Valley.