It gives the licensee the ability to distribute the binary, use or include it in their products in the same way as an open-source product. It just merely prevents modification without decompiling (which i assume is not easy given it's clojure, not to mention obfuscation?). And presumably it makes it less likely someone would just produce a competing product if they should choose to re-monetize it?

Yeah, it's a complete bullshit move. Mongoose OS (an embedded iot Plattform not the db) does something similar. It's extremely weasely and doesn't instill trust at all.

I saw Fabrice Bellard do it this year (MIT): The CPU version is released as binary code under the MIT license. The GPU version is commercial software. Please contact fabrice at bellard dot org for the exact terms.

https://bellard.org/ts_server/