If all innovative Dutch people starting cool companies leave Holland, how can we create our own silicon valley here? Is that really the only solution if you don't want to make crud applications for businesses, to just pack and move to the US?
You do it with laws that make it easy to start a company and that make it cost-effective to invest money in a local startup. Tax reductions are one way. Simple processes are another. Labor laws that distinguish between startups and established companies are yet another.
Here in Brazil we have labor laws that more or less make it prohibitively expensive you from legally starting a tech company, bureaucracy that's absolutely maddening, and an equally insane tax code.
Stopping people from moving isn't the solution to fostering innovation.