The statistics are also totally different (right now), which affects their risk profile. You probably wouldn't have gone to it if it were hosted in China. Or maybe in a year or two from now if double-digit percentages of US residents become infected. But right now, it's not a hugely dangerous gamble.

Even if you do catch it now in the US, if you're not very old or have other health issues, the healthcare system has enough slack space to treat you (potentially crippling debt afterwards notwithstanding), and you'll almost certainly be fine. This may not be the case in the coming months and years, but it's difficult to predict how things will progress (considering there could possibly be vaccines and anti-virals that arrive in time to prevent a full US epidemic).