I also discussed with satoshi, and he said that his employers at the NSA wanted him to create the first P2P currency with a back door in it. That back door happens to be in this specific elliptic curve. Government supercomputers searched for a random elliptic curve that contained a back door.
Just joking, but that's my conspiracy theory. Actually if there is no particular reason for this elliptic curve to be chosen, that is actually suspicious...
If I'm not mistaken, while at the time this was just a conspiracy theory, nowadays we know that something exactly of that kind happened and NSA pushed a cryptography standard exclusively because they had some kind of backdoor for it (some random and incomplete references: 1
We also know that good cryptographic conventions requires to explain how arbitrary constants get chosen, expressly to rule out the possibility of using some particular algebraic field with known (to NSA or others) properties that can lead to advantages when implementing algorithms to break it.
So, each time an arbitrary constant is chosen without explaining how and why, a good cryptographer has reason to believe that something fishy is going on.
Someone says that Satoshi is the nickname of an NSA working group and I really don't care if this is true or not because the code is open source and everyone can verify whether the code and the protocol are sound.
But I'm really not at ease knowing that every signature in a Bitcoin transaction is implemented using a very particular and unusual elliptic curve that has been selected for an unknown reason that his chooser is unwilling to elaborate on.