OK, imagine for a moment that my IQ is actually average or above. I know it's hard, but bear with me.
There is no shuffling or confusion as to which end I'm holding. At least once that I've done it, I clipped the rope before ever taking the draw off my loop. The situation I've used it was more like I'm in a relatively ok position, but reaching the bolt requires lateral movement that starts putting me off balance or in a
tough spot. Now, reaching to to clip the bolt I could pull off no problem, but the mere fact that I'm holding the biner means that I have a couple inches extra reach for the sake of just getting it clipped in. Now in order to get the rope into the the other end, I have to reach even further with the weight of the rope not helping any as it's at the very far end of the lever and it all may be too far lest I lose my grip on the wall. Don't make me draw diagrams and use big words like "hypotenuse" or "moment arm."
Thank you MS1 for being useful. In the circumstance I recall most vividly, the issue was really one of being able to reach the hanging end of the draw once placed. I've done it a couple other times really just experimenting.