Their name was not inspired by their red color, but by their burning, venomous bites which leave huge weeping pustules. If you are allergic or sensitive, it is worse.
If you had ever been bitten, you would understand the desire to kill them if you can, any way you can.
(Bonus: According to the article, the floating ant rafts are 165% more venomous than usual. I cannot imagine.)
However, you are much more likely to get a bazillion bites, for example if you step in a nest and don't notice it until they are crawling up your leg..
https://www.bing.com/images/search?q=fire+ant+bites+&qs=n&fo...
[1] https://articles.extension.org/pages/34572/why-do-fire-ants-...
My brother was once sprayed with them by the lawnmower. He was in shorts (so his bare legs were inundated) and he reacts a lot worse to them than most people I know. I took over the lawn mowing for a few weeks after that.
https://www.sciencedaily.com/releases/1999/09/990923071322.h...