It’s the same reason the media hate posting Per 90 stats for any of our players when doing comparisons to historical tallies of rag, dipper, or arse players or teams.
They put past numbers to absolute shame.
For instance, Ryan Giggs—the current all time PL assists leader—has 62 more assists in his PL career, but played over 46k minutes, whereas Kev has gotten 100 assists in just over 18k minutes. Kev has played 39% of Giggs’ minutes but has 62% of his assists.
Kev is demonstratively more productive, but media outlets never want to make that clear as it would alienate a large portion of their viewer base.