MediaWiki is used to run thousands of wikis on servers all over the world. The 900 wikis of the Wikimedia movement are important members of that family; and the English Wikipedia, the largest wiki in the world, is especially notable. But MediaWiki has a much wider userbase than those few projects. MediaWiki is used to run wikis whose goals are fundamentally different to the Wikimedia movement wikis; to run wikis whose principles are morally objectionable, non-neutral or biased; to run wikis whose content is not open source; and thousands of wikis which are not free to edit. The MediaWiki developers make software changes to accommodate the needs of this entire family; they do not make judgments about which projects are or aren't worthy of support.
As such, the MediaWiki developers represent their own project with their own separate community, with their own goals and practices; and those goals and practices, while closely matching those of English Wikipedia or whereverwiki, do not necessarily precisely align. There is nothing unrealistic, or wrong, with English Wikipedia having goals which are different from those of the MediaWiki software as a whole. The Wikimedia movement wikis have, and always will have, a particularly strong symbiotic relationship with the MediaWiki project, and often have the loudest voice in guiding MediaWiki development. But as a member of a Wikimedia project like Wikipedia, do not make the mistake of thinking that MediaWiki, or the MediaWiki developers, exist only to 'serve' your project, or to serve the Wikimedia movement as a whole.
If you are a member of a Wikimedia project like Wikipedia, you should think of the developers in exactly the same way you would think of the Wikimedia Commons community. Most Wikimedia movement wikis have a strong and healthy symbiotic relationship with Commons, and the Commons community generally does a fairly good job of balancing the needs of the many wikis it supports. But that relationship is usually not without its moments of tension, and sometimes wiki communities do not feel that they are getting everything they would like. But there is an instinctive recognition that those communities have no 'right' to expect any more cooperation than they get, because Commons is its own project with its own values, and that they will have to convince Commons that whatever it is that they want to do is in the best interests of *both* projects, in order to progress. If you treat the community of MediaWiki developers in the same way, you'll understand much better why things do not always appear to be going the 'right' way.
- Do be proactive in letting the MediaWiki developers know when a change has had an impact on your wiki project, either positive or negative.
- Do suggest changes which would benefit your wiki.
- Do keep in mind the 'big picture' when discussing changes.
- Don't ever assume that the MediaWiki developers have a duty to consult your project before making a change, especially if your project is large and self-important.
- Don't assume that the MediaWiki developers have a duty not to make any changes which are detrimental to your project.
- Don't try to argue that a change must be made because there is "consensus" from your project to do so. A consensus of MediaWiki users would be an impressive thing indeed, given that many of them would disagree on the color of the overhead sky.