Missing 'yes' values in other users' exported CSV

I’m trying to cross-reference favourited, disliked and watchlisted films of different users (some are friends some are not). So I use the export function on their checks, favourites and dislikes lists. But when I scan the CSV files I only find ‘no’ all the time in those columns. I’ve tried with more than 20 users with thousands of checks and plenty of public favourites and it’s all the same. It doesn’t happen with my own data, however.