In my childhood recollection the Queen was seen well up until Diana's death. Not sure if she was particularly loved, but don't remember many taking issue with her or the royal family up til then. Then she and the rest were seen as cold, heartless, etc. when Diana died and they refused to fly down. The conspiracy theory that the Queen or 'the Firm' had had Diana killed - especially tied with the idea of her being pregnant with Dodi's child - is a good indicator of how they were seen at the time. But I think the Queen was consistent, diligent, dutiful, and that won people over as the years passed - then the Queen Mother passed, Will and Harry hit their teens and were good looking for a spell, etc.