With coffee in hand, he slowly approaches the key board
You guys certainly like to get carried away, don't you? I've never said no sandbeds under any conditions.
For one thing, maybe we need to define what eutrophic really means.
""Having waters rich in mineral and organic nutrients that promote a proliferation of plant life, especially algae.""
It does not mean a "dead zone". When a area goes eutrophic, there is still plenty of life there. It's just that the life that's sensitive to phosphates is either dead or long gone. You still have crabs, starfish, anemones, some sponges, and some types of corals, etc - anything that's not bothered or will tolerate it. You can even set up a "eutrophic" aquarium - which a lot of you have - and there's absolutely nothing wrong with that. Mushrooms, leather corals, some anemones, etc - a beautiful eutrophic tank.
The only problem is, when you get into housing things that will not tolerate eutrophic conditions, like reef building hard corals, some sponges, gorgonians, etc. They will not tolerate eutrophic conditions in the wild and they will not tolerate eutrophic conditions in a aquarium either.