THe value received is a good argument. It all depends on what we call "value". Money? well, going to the Moon stopped because it had no real commercial goal.
Strategic? Well, the Moon is too far to have a military value.
Scientific ? Well, we agree I guess. The Moon has a tremendous scientific value, but it pales in comparison with its lack of commercial value, at least for those who first look at their wallet.
Educational value? Well, it seems totally worthless in the eyes of so many, but it's around the age of 10 to 14 that one can get the passion for space, while at school. To inspire is hard and unexpected but it can work and then it becomes priceless. Last month, I was able to show the heavens at a group of girls in the Ardennes and some did express a genuine interest. Triana's first goal was educational.

Raoul