Sure, there's a few people like that, but there's even more people who don't care about the Leafs. Why would most people care about a team that hasn't won anything since expansion?
I do agree that judging a player based on playoff success alone is flawed. But that's not what happening with Matthews. He's being judged based on the fact that he's 0.87 PPG in the playoffs over his career, behind guys like Scheifele and Zibanejad. For a guy that can put up big regular season numbers and win awards like Matthews, that's simply unacceptable.
Again, I agree that once all the guys who proved that they could win were off the board, someone like Marino would be a top choice. But even among his peer who didn't win, in that second tier, I'd probably take Jim Kelly over Marino.
And I doubt that your opinion about how they might have done matters, but whatever helps you sleep at night.