If PG doesn't like my comment he can delete it or ban me. I am saying what I am thinking based on my experience with arpgs. Sure this tool would be useful for some, and I know there are people still modding the game, running seasonal ladders and so on trying to keep it up for some time. And with all respect to the original it's time to move on and clearly this person has skills and passion so I suggest a way use it.
I love the original Diablo 1 and Diablo 2 and I don't want to work on newer stuff. It's like saying "Why you still playing Chess? That game is like 1500 years old". Sometimes you need to do what you love, it doesn't matter what other people think or do. Enjoy your own life and do what you like. Simple as that.
I don't fully agree with a chess analogy, because chess has certain completeness and perfection to it so there isn't really much to improve or innovate on. Where arpgs went a long way (paved by D1 and D2) in terms of user friendliness, content, entertainment and so on.
One example that you know for sure is that respecs were not in the first versions of D2 and were added later in a limited form of quest reward and later on became farmable items in unlimited quantities and is a universally accepted improvement which all other arpgs do today.
And of course you enjoy what you do, my suggestion is to iterate on that, not to remove that aspect. This tool is a job well done from what I can see anyway.