Sure it is useful on the server. In no particular order:
1. The journal digitally signs each entry with the entry contents and the hash of the previous entry, so that for an attacker to insert a spoofed entry or remove a valid one they have to alter the signature on every entry after that point or else the signature mismatch will be detected. And you can still also send logs to rsyslog if you want.
2. Faster boot time does matter for a server - when you need to move physical boxes, add hardware that requires a power cycle, and so forth less time to restart is helpful.
3. You don't need to run "piles of things" with systemd. It's modular, so you only need to compile in the services you want.
http://freedesktop.org/wiki/So...
4. Systemd lets you set limits on resource usage by each service: memory limits, CPU limits, Block IO limits, etc... which is useful on the server.
5. On-demand socket-driven service start is useful, so ssh is available 100% of the time but sshd isn't actually consuming resources until it receives a connection attempt.
6. Per-service private
/tmp directories, configurable read-only access to some directories, so a hacked service can't access information it should not or make invalid writes.
7. Because of the use of cgroups in the Linux kernel, when you halt a service you can be confident there are no uncleaned resources - threads, forked processes, file handles, etc... left in use.
8. systemd is compatible with services written in any programming language you want, including shell scripts, so you don't have to rewrite your custom SysV init service in systemd. Just spent a few hours in the documentation to make the text file you need, and you're set.