This is certainly true. Both sides are misinterpreting the statements of one or a small number people as the opinion of the community as a whole, and this is counterproductive for everyone.
I expect that much of this misunderstanding comes from cultural differences: in a closed source project (like the original games or cncnet) the feature list is controlled by a small group of people, and if those people don't want to spend time adding a feature then it won't be included. In a project like OpenRA, just because we (the main developers, who each have their own plans and goals and may not be speaking for the project as a whole) don't want to spend time on something doesn't mean that it will never happen. It is important to distinguish between "We don't like this, and don't want it in our project" versus "we don't plan on adding this, but will accept a patch that adds it". The latter is a statement of fact rather than a rejection. Saying "do it yourself" is very much not the same as no to us. Would you prefer that we said "Yeah, sure... we'll add that eventually" while knowing that we had no plans to actually do it?
The left-click mouse orders is a good example of this: while I expect that the original responses to this request may have been harsher than necessary, it reflects the fact that we consider the left-click scheme to be outdated and less useable than the now-standard RTS right-click scheme. We were stating a harsh truth that we had no plans on adding a feature that we would never ourselves use, but I don't think anyone ever said that we would reject left-click orders completely.
Somebody eventually took up our offer of adding this feature themselves, and it was merged into the main project (#2579). There were unfortunately a few usability issues (#3153) which really should have been caught during the code review (we are stricter with code reviews now, and work with the author to help resolve these kind of problems before their patch is merged). These haven't been fixed by the main team because we ourselves don't use this scheme, and again nobody wants to spend time fixing something that doesn't affect them personally (remember, we are all volunteering our time and effort).
We started using bountysource a while back, which gives non-developers a way to help incentivise features that they would really like to see included. I hesitated before mentioning this, because I don't want this to be interpreted as "we will only add X if you pay us". The bounties were introduced as a way for people to constructively donate towards the people actively working on the project, while sidestepping some of the issues about receiving money from another company's intellectual property. It also means that a developer or outside contributor might decide to implement feature X with a bounty instead of feature Y that they would have otherwise worked on.