Recently someone going by the name "patio11" on the Hacker News forums summarized a chat among Bitcoin developers that took place on March 11 and 12 of 2013. During this period, the Bitcoin Core client 0.8 was released, which created a hardfork that was not fully supported and adopted by the miners.
A hardfork is a change to the Bitcoin protocol that requires the Bitcoin network's acceptance and adoption. Any alteration to the Bitcoin protocol, such as changes to the block structure or difficulty rules, or an increase in the set of valid transactions, is considered to be a hardfork. Some argue that the process to apply new changes to the protocol is slow, and such changes can be dictated only by certain individuals or a small group of people.
The fork that occurred in 2013 caused a rollback for those who upgraded to the newer version. Pieter Wuille, a top Bitcoin developer and contributor at the time, asked miners to roll back to version 0.7, and he sent an alert on the Bitcointalk forums to ask merchants to stop processing transactions until further notice.
The incident provides an example of how hard it can be for these hardfork alterations in newer versions to kick off within the network and among miners. A shortcoming of the currently used Bitcoin core protocol is that it isn't implementation agnostic, meaning only a supermajority of Bitcoin nodes are running the Bitcoin core software, thus core developers can dictate protocol features.
Despite the fact that Bitcoin was first developed by Satoshi and then maintained and upgraded by a certain group of core developers, it has never restricted or imposed anything against the desires and opinions of the majority of the users and miners. In this way, modifications in the hardfork wishlist are only gradually implemented and added.
If we take a closer look at the Bitcoin protocol, we figure out that the only reason for its existence is that it is decentralized, it is strictly verified and it provides a consensus regarding the state of all the coins. At the end of the day, either the majority decides to accept a fork, or they do not. Such a decision can be guided and led by certain people, but it cannot be enforced by anyone.
Similar examples have occurred within the W3C (World Wide Web Consortium). The consortium put a lot of effort into XHTML specifications that were eventually found by developers and users to be incompatible with existing real-world implementations and requirements. Therefore, XHTML was largely neglected, unlike HTML5, which came later and was easily adopted by everyone.
While it is true that Bitcoin is quite slow in adopting changes, this can be seen as an advantage because it requires a consensus of the majority of its users in order to implement a new alteration, which makes it a democratic system. These changes have never been, and never will be, dictated to the users by anyone. Changes to the protocol can only be suggested and adopted if they truly add benefit to everyone, and this is why we all love Bitcoin.