Earlier quoted context omitted.
"Not sure what you mean by 'poorly researched'." I mean that it was poorly researched. There was no definition of security, no mention of the vast body of related work in digital cash or secure multiparty computation, a weak security analysis, no mention of the fact that polynomial time attacks are usually considered to indicate that a system is not secure (one would think that a different security model would requir…
Real-world cryptography often doesn't have security definitions, e.g. AES. In parts that is because security definitions tend to be asymptotic (which is a massive simplification), and real cryptography is working at a fixed parameter. Coming up with a good security definition is hard, the 2013 Turing award was given for one. I think it will take a long time before we get a realistic security definition for Bitcoin.
Block ciphers do have security definitions; what AES lacks is a rigorous proof that it satisfies the definition of security for a block cipher. There are different definitions for different notions of security, but that does not mean there is no security definition. It is also untrue to suggest that security parameters are fixed in practice; this is certainly false for public-key cryptography, but Rijndael was designed to support arbitrary parameters, as are many other practical block ciphers and hash functions.
"Coming up with a good security definition is hard, the 2013 Turing award was given for one."
Not one definition, but several definitions and an entire paradigm for definitions. The work also set the groundwork for proving that cryptosystems and cryptographic constructions meet such definitions.
Really, the importance of having a security definition cannot be understated. Without a security definition, you cannot have any falsifiable claims about security. If I claim a system without a definition is insecure, you can always refute me by claiming that the system was never designed to defend against my attack -- which is technically correct, because without a definition the system cannot be said to be designed to defend against any attacks.
Also, note that I did not say that Satoshi failed to give a good security definition for Bitcoin. What I said is that Satoshi failed to give any security definition. If Satoshi had given an unrealistic or otherwise bad security definition, then we could have a productive conversation about the definition and about whether or not Bitcoin satisfies it.
"I think it will take a long time before we get a realistic security definition for Bitcoin."
The thing is that we do have realisitic security definitions for digital cash -- the definitions just happen to rely on the existence of a central authority that issues the currency, which is a deal-breaker for the Bitcoin community.