You are right that clean code is simple code. However, you have to be way more advanced and think way harder about the architecture and implementation to create simple code. And this is where SOLID helps us. Not everyone is born knowing how to break a complicated problem into simple, cohesive pieces. If you follow the SOLID rules by rote, yeah, you'll wind up with something that's nearly as much garbage as if you didn't follow any rules. However, if you use them as a set of principles that help you to uncover the simple in the complex, then you will be well on your way to being a senior engineer--someone who can write simple code a less-experienced developer can understand and extend without screwing it up.