That's the trouble, the standard makers never think far enough ahead, so companies end up doing their own thing, in many different incompatible ways.
As for bluetooth, it's a very handy convenient way to transfer without setting anything complicated up. If I meet Mr Smith and want to give him a photo from my phone, Bluetooth is the easiest way. Oh, unless he has an Iphone. Apple don't give a flying intercourse about their customers, they just want them to pay vast sums of money to itunes, therefore deny them getting files from anyone else lest they circumvent the itunes payments.
That actually happened to me twice. I was at a zoo, and the automated boards for feeding times were busted. I had gone to reception and she had the times on her computer screen, so I photographed it with my Android phone. When I met a woman later on grumbling at the broken sign, I said I've got them here on my phone, then tried to bluetooth them to her. Didn't work, no error message, just didn't work, we didn't know why. But she did say it was "random if it worked or not". Then when I got home (I was staying with my aunt who also has an iphone), I tried to send hundreds of photos to her with bluetooth. Again, same problem. So I looked it up on google. And found out about the Apple utter scam. Why do people fall for that company's nonsense? Yes, let's pay more for a phone where the battery runs flatter quicker, the camera is lower resolution, you need different apps than everyone else, and you can't transfer files to them.