I'm sure it's been said before, but for those who are technically knowledgable, it is easy to overlook. What Steve Jobs essentially did at Apple was to seamlessly integrate software, hardware, marketing, and customer service into a whole product experience targeted to consumers who wanted an appliance that helped them do practical or enjoyable things. This target audience cared little for hardware specifications or for software provenance, and had not the least interest in how anything worked. They just wanted to work it.
It is that vision of what technology could do--not for engineers or hobbyists, but for ordinary consumers--that distinguished Steve Jobs from anyone else. Those who fail to appreciate the importance of gorgeous design, clever and personable advertising campaigns, knowledgeable and friendly sales and support personnel, and of ease of use, may never understand why so many spent a moment today to mark the end of the active career of a unique American genius.