I recently got married and was very surprised that around 20% of guests did not bring a card or a gift. I wouldn't dream of going to a wedding without at least a card. If I had forgotten the gift, I would acknowledge it upfront. I had never given this much thought, but due to the sheer amount of my guests who didn't bring even a card, I'm now wondering whether this is more common that I thought.... Keen to hear other people's opinion on this!
YABU - you don't have to bring a card / gift to a wedding
YANBU - you should always bring at least a card to a wedding