I'm sorry, but the 'misunderstood genius' argument can only go so far.
It's a good thing no one is making such argument, then. I'm sorry, but boxing strawmen only goes so far, too.
(what people are actually saying is, your perception of "filler" is purely personal and as such not really worth much as argument)
edit: also:
I also play the game and like it for the most part, but I'm not going to stay blind to all the problems it has. Some of those are so obvious that it can only be inferred the developer made them to prolong the lifespan of the game.
All these elements you've listed as "padding" i.e. minigames, free roams, collectibles etc, are present from the very first episode of the game. This goes directly against your claim such "padding" has been added more recently as some sort of desperate attempt to prolong the development "because he loves money so much",
after the game became such huge success.
You have also completely ignored the basic counter-argument -- that DPC has so much of game left on his plate still to develop, he really doesn't need to prolong anything to still get paid for literal years.