Put yourself in his position. You make 2 types of music, one type brings you critical acclaim, well respected, but little sales. The other gives you bigger recognition, higher sales, more money. Which one would you pick?
He will keep the cash cow going, why shouldn't he. He may enjoy the music he makes now, so why shouldn't he.
I like Feed Me, but I loved Spor. It is a shame, but as with Zinc, people just move on from styles of music.
Although I bet he has a shit load of finished Spor songs that he could just drop on people. If he's a perfectionist he may not have the time to tweak & finish them. Maybe he said about the Spor album before he did the Feed Me tour, which would have earned him a pretty penny. If it hadn't worked, we'd have a Spor album soon, but it did, so he'll do a Feed Me album instead.