While it's never actually stated, it's easy to assume that the world Sanderson's created here deviates from ours only at the point of Calamity's arrival. It's also reasonable to think that Calamity showed up either very late in the 20th century, or early in the 21st. The reason I care about this? Because I can't wrap my mind around the words "Calamity!", "Sparks!", and "slontze" having replaced ALL OTHER exclamatory expletives in just 10-15 years.

The story was interesting in the way that frayed jeans are interesting: comfortable, and the frayed edges don't impede either the function or the enjoyment... unless you keep messing with the frayed bits, worrying at them and drawing attention to them. Then they become much harder to tolerate. Sanderson's huge problem here wasn't that there was no logic or consistency in his "powers break physics" and "every Epic has one odd weakness" rules, it was that his characters kept pointing it out, practically rubbing the issues in the readers' eyes.