While there have been successful Bitcoin hard forks in the past, the problem with hard forks of the Bitcoin blockchain is that they're, well, hard. Any change to the Bitcoin protocol that requires a hard fork essentially requires near-complete consensus to avoid a potential blockchain split.

For example, there are many individuals in the Bitcoin development community who do not believe that BIP 101's use of a 75 percent majority vote by miners as a mechanism for enabling a larger block size limit is such a good idea.

Hard forks are difficult, but they have to happen from time to time in order for Bitcoin to grow and evolve. For this reason, some have proposed the idea of scheduled hard forks. This would essentially create a regular update schedule for the blockchain for changes that require a hard fork during the implementation process.