For what it's worth, I clicked the comment thread here before looking at the article. And without recognizing the author's name, my first thought from what people were saying about it was "It sounds like we're talking about Avernum."
I played the demo of one of his games on a bondi blue iMac back in the early 2000's. The graphics then looked ok. But it's 2019 and new titles don't look better.
I've wondered before who the userbase is for these; is it just fans from back in the day when game development was a smaller thing and the competition didn't have great artists either? Because I can't see getting into them as a new player.
Being able to sell 2x by having a more consistent and up to date art style honestly sounds low to me. Even as someone who's played my share of RPGs, had a Mac back in the day, and know that Spiderweb Software exists, that's the main thing holding me back from checking it out seriously.
But if he's getting by with what he's doing and spending more to try and reach a broader market is a risk he doesn't want to take, that's his call.