Tell me which recordings and I'll believe you. And don't say Evelyn Glennie. Yeah, she misses notes, but nowhere near 60%. 60% is a lot of notes--more than half--whcih would render a piece of music essentially unrecognizable.
Your larger point seems to be that marimbists need to get their acts straight and have higher standards with regards to accuracy--the standards of say, a violinist or a pianist. I just think that's rubbish. There are great marimbists and bad ones... good violinists and bad ones... and on and on. I just heard a pianist today try to play a Chopin Waltz. It was WAY over her head, much too difficult for her. See my point?