Because he's white and European, so he doesn't get the attention he deserves in the media, further boosting the voter fatigue.
Kendrick Perkins calling out that voting for him is racist (!), and basically saying that Dirk and Nash only won because of racism against black players(!).
It's a bit tongue in cheek from my side - but I do believe (white) European players don't get the praise/hype/attention they deserve.
I think Perkins comments were very inappropriate and perhaps they affected Jokic mentally a bit, but I don't think that swung voting at all. Actually many journalists got upset at Perkins.