It's not easy to train a neural network. Even if they're not difficult to implement, it can take hours to get them ready no matter how much computing power you can use. OpenAI researchers may have a better solution: forgetting many of the usual rules. They've developed an evolution strategy (no, it doesn't relate much to biological evolution) that promises more powerful AI systems. Rather than use standard reinforcement training, they create a "black box" where they forget that the environment and neural networks are even involved. It's all about optimizing a given function in isolation and sharing it as necessary.