For me it's less the verbose syntax but more the weirdness and inconsistency of it. Like making a distinction between a procedure and a function, or returning data from a function by assigning it to a magical variable. It feels like a cobbled-together language rather than a properly designed one.
replyI wasn't able to find a definitive account of why they're separated in Ada, but I believe the idea is this: functions are for where code behaves in a roughly functionally pure way and yields a value that should not be discarded by the caller, whereas procs are for functionality with 'deep' side-effects.
replyThe SPARK subset of Ada comes pretty close to enforcing purity of Ada functions, although it still permits them to read globals. [0]
It's not just an oversight. The core of the Ada language was designed deliberately. [1]
[0] https://learn.adacore.com/courses/intro-to-spark/chapters/01...
[1] https://en.wikipedia.org/wiki/Ada_(programming_language)#His...