There are a lot of reasons to hate Antifragile: the author comes across as arrogant, is verbose and uses obscure vocabulary, and goes out of his way to repeatedly insult large segments of the population. Nevertheless, I think the book is a useful read in that it helps the reader think about and understand a very useful mental model.
A lot of things die or are weakened by volatility. A glass in an earthquake, an over-levered firm in a recession, and a fad over time are all examples of things that are fragile. We spend a lot of time/effort/money trying to prop up fragile systems. Bail-outs of firms are a good example of that. Instead, we may better spend our resources building systems that are anti-fragile. Letting firms fail makes the economy antifragile, for example.
Nature provides us some great examples to emulate, for it is the ultimate antifragile system. While each individual organism or object is fragile, it contributes to the antifragility of the entire system.
While there are a lot of pearls of wisdom within the book, there is also quite a bit of pettiness. Every other page seems to include some shot at various groups including bankers, Harvard, socialists, MBA's, or any one of the numerous groups the author appears to look down upon. But the author's own controversial reputation may be self-serving, since controversy (a form of shock, or volatility) only increases the revenue of a writer, which is an antifragile profession!