Garbage in - garbage out does not mean that quality in - quality out. With grabage in you always get garbage out. But with quality in you could get quality out only if what is between in and out works properly. In all other cases you still get garbage out.

Back to the analogy in post, even you have perfectly educated and developed humans that have quality input, that does not mean that as a result of their activity you will get something good out, if, say, there is dumb authorities that interfere with process. There still be crap on the output.