You guys can discuss this until you're blue in the face, but let's think for just a brief moment about which of these explanations seem more reasonable and plausible:
A) Voters chose MacKinnon because they thought he had the slightly more impactful season
B) Voters chose MacKinnon because they don't like Russians, feel bad that MacKinnon was runner up a couple other times, felt Kucherov was a little rude at the all-star game, and/or some other ancillary reasoning not mentioned above
I'd also suggest that because the players voted MacKinnon overwhelmingly for the Lindsay, that the nationality/voter fatigue/all-star behavior explanations seem to hold even less water (if that's possible).