Real: You point out that having this commentary won't end the arguments because we still won't know what The Bros were thinking.
This is true, and it is my guess that this is exactly why they won't give the commentary themselves. They don't want the arguments to end.
Before you get annoyed with them, ask yourself this: Did DaVinci explain why the Mona Lisa smiles??? NO!! Part of the reason that this or any other art is great is that every person reads their own interpretation into it. Some interpretations are better than others, but none is "right". As long as the art (be it a painting or a book or a movie) is open to interpretation, it is alive, and it grows with each new set of people that experience it. If the Bros told us exactly what to think, this process would die.
Although I would LOVE to hear The Bros commenting on the trilogy, they are carrying on in the tradition of many great creators who refuse to comment in detail on their work so that people have the freedom to decide what the work means for themselves.