Apparently, Neilsen has disabled reply-all for all their Outhouse users, to “eliminate bureaucracy and inefficiency”.
What an incredibly stupid idea. Removing a very useful feature, just because a few people use it incorrectly? Stupid, stupid, stupid.
If people were CC’d on a mail you receive, then that mail was relevant to them, and contained info they needed. There’s a good chance your reply will also be something they should read; if that’s the case, you hit Reply All. If your reply is only relevant to the original author, just hit Reply. Really not that hard, is it?
May be this vary from person to person. If he have disabled this one that means this one is not useful for him/her. Whenever he will find it useful he will start using this one again.