Sibylle,
It seems you didn't read my post well. I expressed concern about the "many plants - often wild collected" not about the seeds.
Then, collecting few plants for the personal garden it is different than collecting in commercial purpose (ie. large quantities).
It doesn't matter if it's done in Japan, China, Europe, America....the effect is the same - on long term, the whole ecosystem from where the plants where collected will be affected. It is not only about the plants, that would be a very simplistic way to look at the situation.