Hi
There are some task that should/could be done automatically by drupal core itself. Besides OPTIMIZE TABLE it'd be nice to making backups (database mainly, but maybe files too?) and for PostgreSQL running VACUUM (http://www.postgresql.org/docs/current/static/maintenance.html)
IMO this is not something that must be built into core. In a contrib: fine, but certainly not in core. I for one, running a flock of sites on multisite want to maintain my backups / optimisations and that stuff in crontab. Having to circumvent built-in backups, that otherwise would break my server backup system would be a hell for me. A big -1 on having backup and optimisation stuff in core. A big +1 on putting that in contributed maintainance or database modules. Ber