There are many factors beyond the quality of product that go into a purchasing decision - things like hype, accessibility, and most importantly, price.
Apple never had much a problem with great design or building hype, but the real reason for their success over the last 15 years has been their ability to provide customers better access to their products and to provide them at more competitive prices.
The iPhone is ( by most accounts ) a superior product to the Blackberry. However, no one was going to buy an iPhone for $900, and without this impressive supply chain, Apple wouldn't be able to get the profit margins they want at $600 ( or $200 subsidized, which is also supply chain management ).
Product is important, and as a culture that builds things, HNers tend to focus on that ( the green light conversation in these comments being proof of that ), but all the logistics of how a product is delivered are just as important as the product itself - and maybe more so - in building a successful company.