I donāt think any of us are really hardline āno, you MUST use your middle fingerā; most of us understand about variety, taking your own path, etcā¦
But Nathan more or less nailed it in my opinion. Thereās a practical reason for the āstandardā, which is to have at least one strong, usable finger on either side of the string. I think this creates more possibilities than using the index; so even if weāre going to talk about creativity and originality, the āstandardā middle finger method should give you more tools for creation.
If youāre the kind of person who wants to learn other peopleās tricks as well, itās also just going to save you a headache. I donāt think switching to this method (if youāre already an index finger person) should be as difficult a switch to make as, say, learning to write cursive with your secondary hand instead of your dominant one.