I guess it depends on what types of books we're talking about. If we're talking about normal books, well they generally don't have to worry about game design so that's an issue inherent to gaming so there should be different standards there.
To me it seems like board games are more akin to video games than they are to actual books, in terms of being designed. And like video games, generally things get patched because the rules can be complex and some interactions are going to be missed, clarifications are going to be necessary, etc.
That doesn't necessarily mean you're wrong that errata are, well, errors that should be avoided. But IMO it seems that with how widespread the practice is, it seems to be the industry standard rather than the outlier.