The headline says it’s the lowest-rated game in the series, not that Mirage is a bad game. The article bases itself on a single data point, which leaves a lot of room for interpreting. Which the author does a little.
But it’s nowhere mentioned or claimed that Mirage is a badly-reviewed game or doesn’t sell well. It’s just the lowest entry so far. And that’s what everybody should take away from that headline, followed by ignoring the hollow clickbaity article altogether.