I hear ya vtminter, but we do this sort of thing all the time...either deliberately or by inaction. Redbugs, aptasia, bristleworms are all deliberately killed by MANY aquarists. Fish are killed all the time either by ignorance in mixing unsuitable species, as feeders for larger predators, or even deliberately in cycling new tanks. Corals are killed all the time by mixing with fish that will consume them or by placing them in too close proximity to other corals that will do the same job.
Some specimens such as xenia have growth patterns that make this all but inevitable. Yeah, it's great to give all excess specimens away but the reality is that there are not enough takers, even if it's free, for all the xenia in the world. Do you have another alternative? This thread shows how many of us have problems with too much xenia and how many takers are there for this free stuff?