In the sciences you'll notice that simultaneous discoveries are nothing unusual, once the groundwork is laid the idea hangs in the air, you do nothing but reach out and catch it. The Zuse example is just another instance.

In the case of mathematics and computing, the invention can be copied easily by development costs are minimal as well. These is no compelling reason why someone should reap disproportionate rewards from a government-supported artificial monopoly. Progress suffers and the economy as well.