Rank polymorphism is genuinely important and useful and a lot of languages are missing it.
Cryptic symbols, I agree, less so. If your language doesn't arbitrarily restrict identifiers then you can just define the APL operators as functions and write code that looks like APL - I tried doing this in Scala once, and it worked ok. But it's hard enough to convince people to take the time to learn what "map" or "filter" or "<* " does, never mind anything further in that direction.
Cryptic symbols, I agree, less so. If your language doesn't arbitrarily restrict identifiers then you can just define the APL operators as functions and write code that looks like APL - I tried doing this in Scala once, and it worked ok. But it's hard enough to convince people to take the time to learn what "map" or "filter" or "<* " does, never mind anything further in that direction.