Classic case of perspective skewing interpretation.
Mecir was awesome to behold when he was on form, but he was a man without a slam to call home. He had that effortless movement, and could do magical things with the ball once he got to it. But those things masked some fundamental shortcomings, specifically, lacks of athleticism and fitness.
Clay was his most natural surface, but he got ground to death over two weeks of five setters. Held his own much better over best of threes.
Was a fish out of water against a fully stocked grand slam field on the fast grass of his era.
Had plenty of teeth on hardcourts, but ran afoul of the modern, emerging era of power brokers (Lendl, Becker, etc.) who were simply able to hit it so hard that he couldn't glide to the ball and do his thing often enough.
Wilander? Played right into his strengths. Hit high-percentage balls, at relatively low velocities, and tried to outwait his opponents. That's a nightmare plan to try to execute against an artist whose only shortcomings are whether he can get to the balls you're sending over. I think if they'd had any meetings at the French, you'd have seen Wilander's tactics turn the tables despite playing into MM's strengths, because Mecir simply didn't pack the endurance needed to slog through the grinders that made up 80's clay court specialists over the course of five, round after round. MM got to Wilander at Wimbledon in a five setter...but Mats was even worse suited to fast 80's grass than Mecir was.
No, he was never going to win slams without a miracle draw. (Two finals, but utterly uncompetitive in either.) Still though, maybe my favorite player of all time to watch on those precious occasions when he was firing on all cylinders.