Just look a all the stores out of business in the last 15 years. When I was a kid, before internet shopping, I'd get my parents to take me to 5-6 shops in our town. Now there are 2. This is a hobby on the decline.
Buying wild harvested corals, which are regulated, helps sustain indigenous populations. When they make there living, caring, maintaining and harvesting reefs, people are more likely to protect them. Otherwise they subsistence fish and cut down rain forests and fill in marsh lands for farming. Not to mention fertilizer and animal waste runoff. The reefs need these filters found on land for survival.
Two good examples. We have killed the everglades, the reefs in the keys are not even close to what they used to be. Removing marshland and farming in Australia has increased nutrient levels in the great barrier reef which directly corresponds to crown of thorns starfish outbreaks.
We need to support sustainable harvest and macroculture in the pacific, this may be the only way to get the indigenous people to care for the natural reef habitat, instead of destroying it like we have.
this is across the board with any hobby. it's mainly due to the internet. far less over head and far more customers available from e-shopping