My immediate reaction was yes, you're right, it would have been nice if they had stopped to shake hands. But then I realised that that would be a little bit "celebrity" and would set a precedent resulting in more and more people crowding for a handshake at every event, which would lead to the couple having to split in two directions to shake everyones hands either side and resulting in the crowds making a preference as to whom they wanted to shake hands with. I'm all for the royal couple sticking side by side, not shaking anyone's hands so no one is disappointed that those on one side got to see them close up etc. By doing this, everyone gets to see the same thing and no one is disappointed!