> smuggling
Taking something personal in the space assigned for personal use is not smuggling.
> schlocky trinkets
Envelopes from space are pretty neat and evidently highly valued by the people that ended up buying them. Those people now have something that is nearly unique and very special to them. Have you personally ever created or done something as meaningful for other people?
> national significance
No doubt. But how come a government bureaucracy like NASA can't make cool memorabilia like that to give to the fans that payed for all of it but can only watch?
> international spotlight
Few people cared about Apollo 15. It's actually already legendary how hard the public interest dropped off after the first few landings.
> triumph of capitalism
It is a triumph, absolutely. Hundreds of people got something really meaningful for them that they would not have gotten otherwise. The astronauts got a well earned pay off. Humanity got artifacts that will be preserved down the ages. Nobody was hurt or exploited. Win Win Win all around