I think it is true in certain cases. A successful founder has that 100% commitment to the idea / company. He or she will do anything it takes for it to succeed and will hustle it until it does. Sure, employees can write the code that makes the company run but they don't have that extra drive to have made it a success on their own. On the flip side, some founders are just super-well connected people that just get oodles of money and hire a team to make their idea come to life and have no real ability beyond that.