"Invasive" corals never looked so lovely
To borrow JFK's famous "We Go To The Moon" speech: "We choose to go to the moon keep coral reef aquariums [...] not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept."
Reefkeepers enjoy the challenge (which sometimes borders on masochism) of keeping corals within closed systems. Many of us actually seek difficult-to-keep species to hone our husbandry skills and show off our dedication, leading a few of us to totally eschew corals that grow like weeds - corals such as Xenia, Anthelia, Green Star Polyps, Montipora, mushroom corals, et al.
This reef tank stocked with "invasive" coral species is as beautiful as some of the challenging SPS or azoox reef tanks we've seen. A beautiful reef without the constant babysitting, expensive high tech gear, and frustrations doesn't sound/look so bad, does it?