* It is a dependency hell
* It is resource-heavy on embedded systems
* It is too slow for real-time, high speed control loops
* Huge chunks of it are maintained by hobbyists and far behind the state of the art (e.g. the entire navigation stack)
* As robotics moves toward end-to-end AI systems, stuff needs to stay on GPU memory, not shuttled back and forth across processes through a networking stack.
* Decentralized messaging was the wrong call. A bunch of nodes running on a robot doesn't need a decentralized infrastructure. This isn't Bitcoin. Robots talking to each other, maybe, but not pieces of code on the same robot.