The spell is slightly better than it's given credit for. As a ritual, it can be cast without a spell slot, making it much more usable (especially for the wizard who doesn't have to prepare it). It can send the message to just about everyone in the region, rather than just one person, which is really useful if the primary target is dead.You're missing the point if you compare this spell to non-rituals. For wizards, a ritual requires no limited resources once it is obtained. You can do it whenever you want (assuming you have the time to cast it). This spell - with essentially no casting cost other than time - can impacts thousands of creatures. In the hands of a creatve player or DM, this can have massive power.
In addition to the difficulty of finding good uses, the biggest downside is the opportunity cost. A wizard has to either use one of his two spells gained, or has to find it and copy it into their spellbook. A druid only has to prepare it, but that's one less spell prepared that might be more useful.