"popular with developers" is not the same as actually used in real world scenarios. Show me a real world example of pgsql failover and re-mastering that does not involve a restore and not editing configs. How basic? Not even sybase ASE server needs that. Ingres made change in the 80's, everyone else copied it and built on it. Except postgres. It's the Minix of databases.
Show me any proof, that anything of scale is happening in postgresql. All that big facebook and apple data is happening in cassandra (and foundationdb for apple). Netflix has the same pattern, MySQL and Cassandra. Like the days of yore of keeping big data in file systems or tapes and blob indexes in a RDBMS.