Hard disagree: I never used Datomic and likely never will, and I don't feel like I'm "losing some of the language's value". Datomic is a database. You can use any database you like.
Datomic feels like a natural extension of Clojure for storing data—you get no impedance mismatch, you continue working with Clojure's data structures for storing, querying, and writing data instead of dealing with clunky query builders(or SQL strings), and you gain immutability. Sure, you can use any database you like, but then you're playing the same game as every other programming language, ultimately getting less value out of Clojure and making it feel like just another language—at least for applications that require a database.
I disagree. I tried to use datalog and it was not a natural extension at all, because of the lack of nil handling. I also found that I do not need (or want) full immutability.
I would not compare it to SQL: I do not use SQL because there is no distinction of in-band and out-of-band data (your data and your commands/queries travel in the same channel, which causes a world of pain). But there are other database approaches that work very well. It's not a problem at all to serialize your data and store native Clojure data structures, even better than datomic does.
In other words, I disagree that Datomic is somehow natural or superior: it is "a" database, excellent for certain applications, not necessarily the best choice for every application.
Wow I didn't know about datalevin. There are a few Datomic like databases around by now, this one looks interesting. I have been following Datahike and XTDB.