This may sound a bit apocryphal, but I remember reading somewhere that it was the custom for early photographers to lightly sandpaper the front element of their (new) portrait lenses before putting them to use.

Anyway, I do have some "legacy" lenses with a web of fine scratches on the front element. Some have unmentionable things lurking inside as well, but none of them appear to be affected by any of this in actual use.