And here is where I disagree. Would I play the part originally written for those very low instruments down there? Nope. Simply put, it'd get too muddy down there. That being said, would I move it up all the way to middle C? Nope. I would put it somewhere in between. Different ranges in the piano have different complexions. For example, the very bottom of most pianos are very murky. As it reaches the center, it becomes warmer. As it goes upwards, it has almost a delicate sound. What I'm saying is, the range DOES matter. Think Henesys. Think all that is associated with it. Now think if it still fits if it was sung by a bass.
Or Elgar's Cello Concerto played in that Henesys C5-C6 range. Tell me if it's the same thing.
At that rate, you might as well change the key as well (yes, changing the key changes the mood too. Imagine Henesys in F+ instead of the key given. It would sound less vibrant and lively). Pieces are written in their instruments, keys, and ranges for a reason. If everything were written in middle-C range for the piano, it'd be boring.
In the end, there's more than one way to approach things. Music is an art. As is transcribing. Music can be presented in many different ways, and that's the fun in it: there's more than one way to do it! Perhaps you should get off your high horse, and appreciate the diversity that comes with music, the different methods of learning, the different methods of presenting it, and most importantly, the fun that can come with it. I'm not saying you're wrong. I'm saying there's more than one right way of doing things.