With respect to the blockchain, almost all of the technology is available before bitcoin, but no one thinks it works until bitcoin, so bitcoin is the first successful application of blockchain technology. To the extent that bitcoin is the first blockchain there's nothing wrong with it. If you want to understand the blockchain technology, Bitcoin is indeed a thing that can't go around.
Even though all math functions blockchain utilizes indeed was present and used in time before bitcoin, you can't say BlockChain was available before bitcoin. All letters in this sentence are known for centuries but I'm quite certain that meaning of this post appears first time in history (jeez that makes me proud).
Even though all core principals was known it took a lot of thought and vision to put it all together into working system we call BlockChain.