I'm just happy that this thread has actually got people talking about something without lashing out at each other.
Tom, I hear you, and I can see that you've got opinions that are thorough, but I do disagree with some of what you say.
I think your premise about trying to alter natural balances by introducing foreign species is dead on. Reminds me of a great Simpson's episode. For sure, there are great examples of human attempts to tamper going awry. It's just that I don't see the parallel.
Yes, part of Buoyancy World is to see what, if any, marine life adapts to these structures as nurseries or artificial reefs, but I don't think that's on par with examples like introducing kudzu to control erosion only to see is spread like.... well.... kudzu.
For me, I'm excited because I'm curious. For example, I agree, and always did, with LK that instructors have no business practicing skills with beginners over live coral. That doesn't mean I can prevent lazy instructors from doing it. What I can do, is come together with other shops that normally are in too much competition to align themselves and try and make it easier to get "muppets" where they belong. If Mohammed won't come to the mountain, bring the mountain.... blah blah.
Mostly, I can't stress enough how the good will of shops working together has blown a slight wind of hope onto the island. I don''t think that should be overlooked.
Finally, I get really grey when it comes to comments about "tampering with nature" when the statement itself presumes we're not part of nature. This is one of those things I, personally, can't view so black and white. It seems like we do best if we take it case by case, and, in this case, I see more positive than negative.