1 - 99% don't care / is useless to them
2 - mostly advanced / knowledgeable users of OSM, use fully OSM based maps(like osmand , magicearth etc.), in my country and specially where I live, people use local map application(made in the country) where they only use OSM as a base and a most of the other stuff comes from users(like POIs). roads, ways or similar can only be edited by respective corporate OSM editor of that application(either officially or unofficially)

3 - every little thing except type of the house(residential , commercial etc) triggers OSMose(warning, issues etc.) as for why? read  NO 4

4 - since a lot of buildings here specially residential ones, either they don't follow normal building conventions ( like type of building, levels, house number etc) or they are hard to make sense for average osm contributor(like myself) because they need a lot of nitpicking or reading wiki.
