[kpgiskpg]

That's a question of interface design. You can also create ugly, ambiguous interfaces with functions (10 arguments, it mutates some of them, etc), or any other language feature. If a library designer uses operator overloading well, then it should be obvious what "a+b" is doing if you know the types involved.

On one hand it's a question of philosophy -- do you provide the user with tools to better express themselves, if they might possibly shoot themselves in the foot and create a crappy interface?

On the other hand, it could be an engineering issue. Maybe it's not worth the technical challenge or the increase in complexity for the language designers. I'd be more sympathetic to this reason. Then again, Python and C++ manage it.