A rather important bit from the Wikipedia page to keep in mind when reading that quote: "His account was largely sourced from a 1797 work by Johann Beckmann ti

A rather important bit from the Wikipedia page to keep in mind when reading that quote: "His account was largely sourced from a 1797 work by Johann Beckmann titled A History of Inventions, Discoveries, and Origins.[11] In fact, Beckmann's account, and thus Mackay's by derivation, was primarily sourced to three anonymous pamphlets published in 1637 with an anti-speculative agenda.[36] Mackay's vivid book was popular among generations of economists and stock market participants. His popular but flawed description of tulip mania as a speculative bubble remains prominent, even though since the 1980s economists have debunked many aspects of his account." Also see the "Modern views" section. Basically, as far as anyone can tell Mackay's account of tulip mania is mostly bullshit.