It's interesting that no one cries out over the extinction of species that are harmful to us. Not that I mind; some extinctions are good. Reminds me of a passage from a science fiction novel I read a while back.
"No ballads were written of this great battle; the official account was curt to the point of insult:
"'Technologically Super-advanced and Aggressive Alien Species VI Engaged and Genocided.'
"Alien Species II, III, IV and V had fought longer, more spectacular campaigns, but they were just as dead. ...
"For humanity remained, as it had always been, a decisive and a ruthless species. The Government of the Solar Neighbourhood preached peace and liberty, and tolerance for all sentient creatures. But any alien that threatened the wellbeing of humanity would be eradicated, without a second thought. That was the way it always had been, and always would be."
This results from an anthro-centric cost/benefit analysis, not just a "save the poor deadly organisms", but I expect the same would be true for just about any organism that human science can maintain, and attempts to destroy.
"No ballads were written of this great battle; the official account was curt to the point of insult:
"'Technologically Super-advanced and Aggressive Alien Species VI Engaged and Genocided.'
"Alien Species II, III, IV and V had fought longer, more spectacular campaigns, but they were just as dead. ...
"For humanity remained, as it had always been, a decisive and a ruthless species. The Government of the Solar Neighbourhood preached peace and liberty, and tolerance for all sentient creatures. But any alien that threatened the wellbeing of humanity would be eradicated, without a second thought. That was the way it always had been, and always would be."
Palmer, Philip (2010-10-28). Version 43.