Of course the complexity of having to set a cluster early on doesn’t help for small shops.
Then there’s the complexity of learning datalog - love it, but when I see people already struggling with SQL, I’m not confidant about using it generally !
What part needs a cluster in your experience? The Datomic deployments I've been involved with have been running on a single server, with a single instance of backing storage etc.
Datalog is interesting indeed... Back when I first started using Datomic in 2012 I had just fundamentally decided to use it, and it took probably a week before the query language "clicked", i.e. to be able to actually compose my own queries and not just copy paste my way to something that works.