Which would be why pretty much ever web server and mail server choose to implement their own logging mechanism, right?
Or perhaps its that having to bundle your logs together into a comparative handful of categories and then sort through them is less than entirely optimal.
Daemons implementing their own logging in addition to syslog is a feature, not a bug. With journald, even more so.
My understanding is that for a number of services (postgresql comes to mind) the issue was that syslog isn't implemented on all platforms, notably Windows.