I'm in disbelief over the mental gymnastics going on in this thread.
Matthews is an elite goal scorer. One of the best in the game today.
Firstly, in context of other players in the league today, I could give a shit less about "goals per 60". Goals per game is definitely more relevant, but let's stop extrapolating everything to 82 games just to pump up his tires. The reality is you play hockey and a number of games based on how often you're healthy and/or not scratched (the latter obviously not an issue for Matthews here).
If he's unable to stay healthy, sorry but that does impact how he compares to others. It doesn't make him any less amazing at what he does, but you're insane to look at him putting up less goals than someone else and saying "but he's better if he played more games"; well, he didn't.
In regards to Ovechkin, how this is even a debate is beyond me. Ovechkin is the greatest goal scorer of all time. Matthews has had a few good and great seasons. They are not the same. Right now what Matthews is doing is similar but slightly worse than Stamkos' run, and about the same as Pasta and Drai. It doesn't make him a scrub, in fact it makes him elite - but it doesn't mean he can touch the absolutely phenom that is Ovechkin.