I think I may have said this in the thread that OP refers to (and I'm talking more about OP's post and some of the comments than about the survey itself) but: People of a certain age, e.g. mine, have always felt that things were better in the past. That is largely because things were better in the past: we were young. But if OP and I feel that standards have declined since our youth, and our parents felt (as I know mine did) that standards had declined since their youth; and if their parents felt etc., then if you go back three or four hundred years you ought to find a time of amazingly high standards, where everyone is writing perfectly and no one is making grammatical or spelling mistakes (or mathematical errors), etc. But no matter how far back you go, you will find people making mistakes and otherwise behaving badly, and other people complaining about the mistakes and the bad behavior and saying that things like that didn't happen under good Queen Hatshepsut or whomever. It's always possible that things are getting worse, but a subjective feeling that they are is no evidence at all.
(Back when I had a dial-up connection, I used to keep something to read in my lap while at the computer so I had something to do while the next screen loaded. I'll have to start doing that again. The time between clicking "Reply" and getting to this screen is interminable. That's something that was better in the old days, last week.)
