You can tell me anything what's bitcoin worst enemy is...
Mine is, government!
I think if there are bitcoin's enemy, it will be the users. We all know that the user's are the most important when it comes to it's value, but even so, the users are the most reason why there are some problems in the blockchain. They keep clogging it, there are a lot of users so there will be always a massive number of transactions. Good thing bitcoin is still being developed.
I don't fully agree that it is the users which should be considered as the enemy of Bitcoin. The reason why there is a clogging is because there are many users...and that is a happy problem actually. The sad problem is if no one will be using Bitcoin anymore as that mean the death of that coin. The more activities there are the better for the coin that is why we need to scale up the capacity of Bitcoin so that it can serve more and more transactions.