But this exposes an underlying assumption in their thinking, which is that a deeper game is automatically a better game. I would argue that this assumption is mistaken, especially on mobile, where people tend to gravitate towards games they can play in short bursts during downtime. In that context "deeper" just means "harder to pick up and get into."

That's an arguable point, of course, but I just mean that it's not as axiomatic as they make it sound that Threes is better just because it's deeper.