Even though I've not had much problem unpeeling bananas starting at the end with the stem, I tried opening one by the opposite end last night.
I found no advantages to this rival method.
The stem didn't help me to hold the banana at all.
I was told that there'd be no strings but there were. (I didn't know how opening it at the other end was supposed to prevent strings, so I wasn't shocked.)
More fine-motor control is involved in opening the banana at the tip. And that's probably what drives the evolutionary dynamic here. (The evolution is cultural and therefore Lamarckian; but it is pressured evolution none-the-less.)
As far as I'm concerned, people who want to open the banana at the tip are welcome to do so. But the rest of us are not wrong in opening it the way that we have.