Very few people nowadays the word "decimation" with it's original meaning, and I'm guessing the author didn't here either. Or rather, we should probably say that the word has evolved to mean "an arbitrarily large percentage" and not just 10%. I see that definition listed as #3 in Merriam-Webster, where the original meaning is #1. Those should probably be reversed now. #2, in case you're wondering, is related to taxation. Go figure.
I went to the article to find out that this fungus was apparently introduced ten years ago, which obviously seems to indicates human involvement, and explains why the bat have no natural defense. I think this also justifies human involvement in finding a solution.