The old style syslog does have lots of problems but most of the replacements are worse. You can read syslog output without special tools and it is reasonably easier for programs to parse (modulo the parsability of the logged messages).
I would also note than a lot of things found to large network, for example lights out management and SAN boxes support syslog but none of the other solutions. This makes syslog support an important feature.
It also reasonably easy to set up a drop safe non-networked logging host for cracker proof logs. If the journal, or anything else, loses this or the ability to process the logs without special tools then it is a step backwards.
Knowing that your logs have been edited is not enough: as a system admin I want to know what was edited out and a drop safe logging host provides me with that. Anything that does not support such a box is inferior.