That is a terrible alternative. It is a colossal pain chasing down processes which are still doing open-ended logging into /var/log on a RAM-only system, or guessing which ones may or may not be properly rotating their log files.
The OP is right: some stuff is so essential it should be centralized. Whether systemd is the right way to do that I don't know, but it certainly seems to the compromise we'll live with in the near future. Just as SysV was in the past.
PS: as an alternative you could use a tmpfs to move /var/log (and other log directories) to RAM on an SSD system. Far less configuration required, in my experience. And it works with every *nix out there.