I agree it feels a bit counter to the philosophy of Clojure. It's adding new syntax to the language for map destructuring only (that will need to be implemented in cljs and other runtimes for consistency) and it's a purely runtime check as we don't know the map's keys at compile time. I don't see what new kind of safety it adds that's not achievable with existing solutions such as :pre or doing an assert inline.
I feel there are better solutions to this problem that already exist, such as using spec/malli and validating the value properly rather than just checking for presence.
Clojure is very enjoyable if you respect the practices encouraged by Rich Hickey.
I've worked with Clojure in a number of companies, it's an elegant language and a thing of real beauty when done well, but it's not so much fun when you're working on a codebase that doesn't respect the philosophy of avoiding breaking changes; especially when these breaking changes are done in library code, and where a more liberal approach has been taken when it comes testing.
"less ceremony, more responsibility" is a good summary, in a larger codebase a bit of ceremony is not always a bad thing though. I'm also glad I learnt Clojure, it made me a far better programmer.
Kudos to Mr Hickey, I'm looking forward to the documentary.
I feel there are better solutions to this problem that already exist, such as using spec/malli and validating the value properly rather than just checking for presence.