I think what the parent comment is saying is that, lobster was likely introduced as an elite/rare dish to people in the current century increasing the appeal
That is exactly the point they are trying to make... that you enjoyed it BECAUSE you thought of it as a delicacy and not as peasant food.
I think the point is a little overwrought, really... while our expectation is part of what makes it taste good, it doesn't completely change what we think... there are a lot of foods that are considered delicacies that a lot of people don't like.