Actually if you read my post I gave 2 possible causes to the same problem. The first you are right, has nothing to do with your suggestion or video,...
Well there is no "I've done it all" achievement. Anet is constantly devoloping and releasing new content some you might like some you might not like....
Well it depends on what you deem "worth while" they have added new content and continue to do so. Depending on when you left they've added a new tier...