Bingo, it's the same exact argument I used when people were saying that Marchand or Kopitar should win the Hart. The Hart has never been given for "the most valuable player", the Hart winners and nominees consistently:
1. Are on playoff teams
2. Are at the top of the league in scoring
3. Win other major awards
The finalists almost always have those 3 things being true, with the few exceptions being guys like Stamkos, who scored 60 goals and had a weak competition in his Hart nomination year. People keep trying to warp what the Hart actually is awarded for to say their player deserves it, but that's not how it's awarded. Marchand isn't going to win the Hart because he has the highest points/game in hockey and is "really good defensively". Kopitar isn't going to win the Hart because #2 on his team is a lot of points behind him and Kopitar will challenge for the Selke this year. The Hart isn't awarded like that and has never been awarded like that.
If this would be any other year, I think McDavid would be a finalist. Maybe not win, but he'd be a finalist. But this year? This is a great year for Hart contenders, McDavid is hurt by being on a bad team plus this year being very competitive for the Hart.