Personally, I think it just makes the American Government look hideously ineffectual when the President of the United States of America can't offer anything else in his reactionary speech to a terrorist attack outside of standing behind a podium and going "These guys are losers! Remember that folks! Losers!". It's so infantile, it undermines a government that should be coming across as the stronger, infinitely more civilised side. It's fighting darkness with baby noises, which terrorists will probably only delight in.
We've gone from President Obama delivering intelligent yet blistering speeches denouncing terrorism and offering support to the afflicted victims to Donald Trump sputtering "losers!" into a crowd. I get the idea that's it's better not inflate the egos of terrorists by calling them monsters, but there can be a middle ground between doing that and this. If anything, it gives off the impression that terrorism is winning because it's drawing a much more emotional reaction from the President in comparison to past leaders.