The bitshares merger is overwhelmingly approved by users and delegates. When was the last time Bitcoin development direction were put up for a vote by all users?
Yes, you are proving my point on how one person can quickly influence all the delegates within DPoS.
Your suggestions seem to be well intentioned but clearly show you are unfamiliar with developing open source software. If you try and mandate developers with majority voting you will simply scare them away and they will just work on other projects. Developers either are being paid to develop features by companies or donate their time because they enjoy supporting the ecosystem. Open source software is mainly based upon meritocracy not by majority opinion. If you feel strongly about implementing a certain feature than contribute code yourself , request a pull on github, or pay a developer to do so for you. Their are multiple stacks or implementations of bitcoin that interacts with the blockchain as well. You are encouraged to contribute to those if you don't agree with the direction the Bitcoin core developers are taking bitcoin. In fact, many of the Bitcoin core developers would welcome more development in various other implementations or stacks.
Open source development isn't about democracy, but more closely related to a form of anarchistic meritocracy.