I thought languages were supposed to change and evolve over time?
Well, “rising intonation = question” is a well established convention in spoken English. It seems to me that NOT recognizing it is something relatively new. And, yes, written dialog may indicate it by placing a question mark on the grammatically declarative sentence to convey the speaker’s intent.
I’ve noticed this phenomenon, too. I think it has to do with the emphasis on written tests in the US school system. I remember in my elementary school the teachers absolutely forbade the students from speaking to each other and ran their classrooms more like military barracks than the training ground for citizens in a free society. I remember very well taking fill-in-the-blank tests on SMALL TALK, like, “How are you?” or “Is it raining outside?” without any opportunity to actually practice it. I also remember notes from my teachers like, “Do this in your free time, not on the school’s time” when I would eschew filling in the blanks and write something freely. And I went to school just before it was common to have a personal computer, AND before No Child Left Behind, which, from what I’ve read, has only increased the use of written tests. I always remember elementary school accusingly when I meet these tone-deaf people, who are the majority of people in the US in my experience. I am so sure the main reason is the school system that whenever I hear a politician criticizing the teachers’ unions I vote for them.
Greek is similar. At the end of a question, the pitch goes up, then down.
In My experience it’s been used seldom and only in one word sentences making the whole word higher than in normal speech ( and You gotta raise Your eyebrows ).
If the tone slides up, it’s only in questions like ‘Whaaaaattt?!?!?!?!?’
Ever notice how a dog or cat will tilt their head just like a human when they are wondering about something?
Or the English huh. 
I’ve always thought that using ha’im was a more forceful thing, absolutely declaring the whole sentence is a question. Sort of like a lawyer asking a witness “is it the case that…?”