It is very difficult to do distribution right, and Postgres is extremely conservative when it comes to new features.
Stability, reliability, and performance are #1
Stability, reliability, and performance are #1
Distributed stuff done right is difficult (as seen by Aphyr's Call Me Maybe tests, how few products survived despite high claims in their marketing).
Others that failed redeemed themselves and fixed issues after the results came. I think etcd and Consul devs did that.
So it's meaningless even bringing it up.