Well, you're right in the sense that Newton was right about gravity. It works perfectly down here on earth, but breaks down out in the universe. In a distributed system you'll want to take into account caching, replication, atomicity, security, etc. In other words, that's either going to be a hell of a complex API or an API that gives you too little control to build a high-performance system. There's no telling what works best, every computer system is a set of trade-offs and it always depends on the application.