I'm still of the position that the default ought to be that a normally-functioning server generates no ongoing log output. Only people who have got Nagios watching their logs, or some such setup, are going to want anything different. And that is a minority use-case. There are going to be way more people bitching because their postmaster log overflowed their disk than there will be people who are happier because you made such output the default. (Don't forget that our default logging setup does not rotate the logs.)
Is it known how many new Postgres installations are from
popular packages (that have log rotation enabled) compared
to custom-built and managed in their own way?
If people do not use packages these days, they should take
care of themselves – it includes log rotation and, for example,
autostart. The same people who might complain of overflowed
disks should already be complaining about Postgres not surviving