Sure, you can keep the current companies here, or make them pay up to leave. And it plays well to the left wing base. But hasn't anybody else realized that you'll put an end to new companies forming here?
I worked for a large French conglomerate for 12 years. The CEO wouldn't put ANY new investment in France because of their draconian anti-business laws. So you have one of the top dozen or so companies in France making essentially zero investment in their home country. Sure seems like a great idea to me.