The most common form of "sanitation" is probably abridgement, and I think there is a strong argument that abridgement is a net positive because it allows people

The most common form of "sanitation" is probably abridgement, and I think there is a strong argument that abridgement is a net positive because it allows people who would never be able/willing to read the full book to get the gist of the story and still participate in / understand at least some of the cultural significance of that story. Not terribly unlike reasonably faithful film adaptations. But what the publisher did in this case was not like that; these modifications weren't designed to make the books more accessible to people with low reading skill ('fat' is not a hard word.)