I don't think it's pointless as it documented. Another piece of information like the write offset. Also there are people that believe that there shouldn't be any sector errors (I was one of them) and they might dump a game that it's the database get the same checksum but do everything they can to fix those errors screw up the image, sectors don't match with the original and then post that as a good dump but if it was documented oh these errors are known not trying to pull something here and go along with it. I don't know, that's my thought anyway.
xenogears, I'm not the most knowledgeable about this but I think mastering errors are on every disc of the same run so there could be thousands of discs with those errors and who knows if they didn't make the same mistake for them all. Also like my Easter Bunny's Big Day, I believe Digital Press said they only run it once if there was any mastering errors waiting for a disc without them would never happen. fortunately it didn't though someone that knows more can fix any misinformation I gave if I did.
Three years and still going strong.