A lot of what they are doing dates back a lot further than that. The innovations SpaceX has brought to the industry are more process related than technical. SpaceX has done a great job of setting a streamlined vertical integration for their production processes, which has allowed them to iterate a lot faster than others in the industry.
That isn't to say they haven't been doing interesting things from a technical perspective (they're landing rockets on barges, after all), but the real secret to their success has been taking proven technology and doing it better/more efficiently (for instance, the fundamental design of their rocket engine, the Merlin, dates back to 50's).
Elon Musk definitely deserves a huge share of the credit for SpaceX's success, but there have definitely been other folks who have made (and continue to make) critical contributions.
Just a couple examples would include Tom Mueller, who was responsible for most of the design of the propulsion systems SpaceX currently uses (including the Merlin and Draco engines), and Gwynne Shotwell, SpaceX's President and COO. SpaceX absolutely owes its existence to Shotwell, both its commercial success, and the fact that it didn't die (a number of times) are directly due to her.
From an outsider's perspective (_very_ outside), it seems like it's really the "synergy" of Elon and Gwynne that have made SpaceX what it is today.
There is - having visionary, charismatic founder(s). This pattern has been successful at Apple, Microsoft, Amazon, Facebook, Netflix, Tesla\SpaceX, Google.
The resulting cost savings they (SpaceX) are bringing to the launch market is really amazing. United Launch Alliance (ULA) made a fortune on over-charging the United States Government for their National Security launches. SpaceX is now competing for those launches with a price between 1/4 to 1/3 of what ULA is charging.
Part of that also comes from the pricing model. ULA has often done cost-plus contracts, which incentivize inflating the cost. When SpaceX joined the party, most of the contracts became fixed price (i.e. the government is going to pay $X, and it's up to the launch provider to build their profit into that, and any cost overruns are the provider's problem).
That isn't to say they haven't been doing interesting things from a technical perspective (they're landing rockets on barges, after all), but the real secret to their success has been taking proven technology and doing it better/more efficiently (for instance, the fundamental design of their rocket engine, the Merlin, dates back to 50's).