Most large companies have someone who is responsible for checking all Facebook posts and ensuring that nothing negative is left there. But these people always work in head office and always know what to do about an unhappy customer, so if you do post, although it usually gets deleted, "strangely" you find that someone important responds to your complaint quite quickly after that. I use this a lot for US and UK companies, usually works.
I obviously don?t know the situation of all companies, but based on what I have seen, I disagree.
I also deal with online reputation management, and any company, that only has positive content on their FB page, would appear suspicious to me. A few companies I know, have specific rules, that everything must stay, due to transparency reasons. Like I said above, only pointless swearing and attacks (for obvious reasons) are deleted, but nothing legitimate.
I think nobody expects companies to do everything perfectly, there are normal people working everywhere, so making mistakes is part of life, it?s the way the mistakes are handled, that?s important. Again, if I saw a FB page with nothing negative on it, I?d think there?s something they want to hide.
Besides, how a company can handle public complaints, would be a change to show their prospective clients what are the capable of...