Earlier quoted context omitted.
Just curious - what do you see as its shortcomings?
its not about its shortcomings, its a database. your saying it replaces chef and opsworks. you're missing a few pieces to make that picture. ie. how do i update the load balancer as i add capacity to my web app, how do i setup a new db instance and open up the firewall rules to an app on a different host. etc. docker, and etcd are both nice pieces, but they don't make a complete picture. nor does fleet imo.
Configuration management (puppet, chef, salt, ansible) is a completely different beats than service discovery, health management, etc.