Why is it so hard to create something new?

I last wrote about how somebody needs to buy Palm because they created an impressive and independent smartphone OS, and that can anchor their future smartphone strategy.  
That also got me thinking about why it’s so difficult to create something new and innovative.  

If you think the idea of there being nothing new is new, think again.  Back in 1889, Charles H. Duell, Commissioner of the US Patent and Trademark office remarked: 
“Everything that can be invented has been invented.”
While the quote itself may be disputed, it’s not hard to imagine someone at the time thinking we had figured everything out.  
Before the iPhone, handset makers were stuck with perceived constraints.  Constraints on how much people would pay, how much a device cost to make, existing technology, existing input mechanisms, existing software platforms, existing bandwidth constraints.  

Existing everything made anything new impossible.
When the iPhone launched in 2007, it completely changed the entire paradigm for smartphones. They weren’t even smartphones any more, really just mobile computers.  They snuck up on everyone and turned the industry upside down.  

Now we’re stuck in a new (better) paradigm, but still stuck.  Palm’s WebOS, Google’s Android, Windows Mobile 7 are all flavors of the paradigm that Apple created with the iPhone. 
The one counter example that I have seen is 10/GUI.  More on that later, in the meantime, enjoy this amazing video: