Well put, Silversurfer. To add a little bit, I think the main reason people comment on huge changesets is because if you go to your area on osm.org and click history, depending on the activity in the area, many or even all of those changesets can be accidental world-spanning bounding boxes like this one. I'm of the opinion that using osm.org website directly is a bad way to monitor an area or review others' changes, but it definitely is the most obvious way.
Anyway, thanks for your contributions!