No matter what community volunteer effort or organization, whether local, national or worldwide in scope, there’s a fairly immutable rule of the way people will perceive your efforts:
25% of people will actively support the effort by volunteering, contributing financially and talking positively with their friends, coworkers and family about the work.
6o% of people will be neutral. They will neither support or detract from the effort. They will have a reasonably balanced opinion about the work.
15% of people will have a negative opinion of at least some aspect of the work. Sometimes they will actively detract from and disparage the work. A few may try to stop the work from moving forward.
It is generally unreasonable to think you will eliminate the bottom 15% or that you will motivate many of the 60% to actively support the work. You can keep up the morale of the 25%.
There are times the 15% can be vocal and discouraging. If we understand that they are a fairly constant presence no matter what the scope or type of work you are involved in we know that arguing with them or trying to win them over is counter-productive. We feed their desire for attention and support for their opinions by engaging with them.
Tell a positive story, own up to shortcomings or miss-steps bravely, seek continuous improvement without being reactive.