The data set is paywalled so it's hard to know. If they picked shovelware most people would rather pirate then yeah, they could reach that conclusion easily.
Denuvo could also be just making people forget about the game once the hype dies down so they never end up trying it which ends up never buying it.
Some people also end up buying the game in sale later, or well after they played it. I personally ended up buying a lot of the games I pirating a while back, well after their release.