available). When it does make a difference is when some process goes insane and logs tons of similar lines, at which point the compression allows one to retain such logs without much impact, which I think is valuable.
Maybe the logging facility should filter the duplicate message with something like "the previous message was repeated 348 times".
rotated log files be compressed; there certainly isn't in 10.8. There is an example of a logrotate configuration file that happens to compress the log files, but that's an example, not a normative requirement.
It seems that many package maintainer understand that the rotated logs would better be compressed. Maybe a small sentence could redirect to a space/energy/disk_lifetime trade-off discussion.