Actually, that's not true. There are two ways of keeping one's intellectual property secured. One is through the use of patents, wherein the method is fully disclosed with the understanding it will be legally protected, the other is known as a trade secret. There are legal protections of some nature for both in differing degrees depending on country. I am 100% sympathetic to leading designers keeping their drivers closed to hide implementation details and optimizations the designer would prefer to keep as a trade secret. Anything revealed for patent purposes can and will be ripped off in countries where patent protection is not enforced or not provided. Reverse engineering can reveal trade secrets, but it can at least slow the process down so that some money can be made before the tech is absorbed into China's bank.

As i said, i would prefer fast, modern technology in my device to 100% open drivers. While the two aren't mutually exclusive per se, in practice you don't see it happen because companies want to keep their advantage and with it, profit margin.