"It looks like somebody just got hungry and took a bite out of it," says Haber. He has positioned the record on a turntable and fitted the broken piece back into place, like it's a jigsaw puzzle. "If we spun this thing fast, the piece would come flying off, you know, and maybe hit somebody," he says.
In that particular case, definitely. More generally, it's risk.
Every time an archivist touches the media - no matter gloves, a clean environment, the care applied, etc - there's a risk of altering or even damaging it. In our case, the eventual goal was to keep the ever-deteriorating originals in nitrogen-filled vaults.
Therefore, if you can avoid having to touch it often (or ever), then you've managed to protect it better, probably longer, and more cheaply.
Paragraph 2 of the link.