See https://bugzilla.redhat.com/show_bug.cgi?id=1227379#c25 from Steve Grubb:

I think the root of the problem here is journald. There is a function, server_open_audit() which enables audit even if people don't want it on. Journald should not enable audit, that is the audit daemon's job. What journald should do is:

1. Stop enabling audit.
2. Make it configurable as to whether or not to include audit data in the logs. Because its potentially mixing Top Secret data with unclassified data, there needs to be a way for people to shut that off when needed. If enabled, just attach to the multicast group and listen. AVC's will still come out. If not, open a bug on that. But enabling audit will slow the system down. If you want the highest performance of your system, audit must be disabled since boot and never turned on.
3. Make it configurable as to whether or not to pass audit data to syslog. Again, journald is the only thing that knows the provenance of the data stream. Therefore its incumbent on journald to prevent unintended reclassification of data.

The audit subsystem leaves sending event to syslog as a configuration option. It defaults to off because that is what the majority of the people wanted. Some people want it on, though, so that its aggregated and searchable by splunk. But this is the minority.