You know what I think?
I think that he cannot help himself.
You know, in the "Off Topic" forum, there's a thread called "Japan: It's just not funny anymore" and in there there's an excerpt about how in Japanese culture, when something is popular, then they just build around that one thing that was popular, and just milk the thing dry instead of innovating (I think it was based on the Chokokuro cafe, where there was a cafe that sold hot chocolate and croissants, and just those two items would do well in the cafe... so then they started to just sell those two things, and then renamed themselves Chokokuro, as in Choco=Chocolate Kuro=Kurossant, which is Croissant).
Perhaps IGA is just attaching stuff to what he thinks is a 'tried and true' concept... except that we get sick of the damn thing after enough permutations of the same thing and he doesn't get it.
So yeah like I said, maybe it's a cultural thing... so it's probably good that the new game is being made in Spain where such a culture is not mainstream.