This isn't even close to true. The Xbone has had better exclusive games by any metric.
Sony's exclusives so far have been really damn bad, actually. I haven't checked, but I wouldn't be shocked if the average meta was in the 70s. And for some, like Knack/Killzone/Driveclub, that's EXCEPTIONALLY generous. Those games deserved 5/10 at best. Just straight up shit.
That's my biggest disappointment with the system, actually, besides the 2002 era Mad Catz build quality controller. I hope Bloodbourne is good.
At the end of the day, I'm glad both systems are selling well. But God, Sony needs to clean up the quality of their exclusive games.