Absolutely agree. We just haven't solved node storage management. We need a better way to deal with data storage than simply using StatefulSets and tying database cluster members to a given Kube node.
You can either use local disk (thereby tying to a node) or network disk (fully supported, but apparently not good enough in any number of dimensions) or local+replication which kube does NOT currently solve cleanly.
The model I want to see is fast network-centric access to replicated local data. Some vendors are pushing into this space now. 2017 will be exciting.
Disclosure: I work at Google on Kubernetes