That's the gist of it. No one is opposed to adding support for osgEarth as long as it doesn't subtract from anything else. The issue of osgEarth is slightly complicated by the fact that Jeff built it for version 3.2 or somewhere around that time frame, it never got rolled into the main codebase at the time, again for some complicated reasons, and now we are working on version 2016.2 ... there is a gap there between the osgEarth implementation and the current development version of flightgear that no one (as far as I know) has stepped forward to fill. Also this code would necessarily touch on a lot of tricky core rendering code, so understandably, our existing developers with knowledge in that area are very cautious with changes at that core level. It sounds like Jeff (the original integrator of osgEarth ran out of energy on the project, or other priorities came along, I don't know.) Every time Hooray brings up osgEarth as an example of the process going wrong, I think about still waiting for someone to come forth with patches/port to the current code base who is willing to take feedback and make adjustments.
And has been alluded to here and in many other places ... there is a tremendous amount of work and complexity that has gone into the current scenery engine that osgEarth may not be able to address ... like we know the surface characteristics of each type of land class, roughness of grass/fields vs. tree or shrub areas which affect taxing and our landing gear model. Does osgEarth handle runway and approach lighting at night or in bad weather? That's a pretty important aspect of flight sims. Can osgEarth tell flightgear if an airplane is touching down on water or land? Photoreal scenery has a challenge where all the details and all the 3 dimensionality fuzzes away into a big messy blur when you get close to the surface. Airplanes, shadows, time of day, buildings, cars are all frozen in time in the imagery ... this may or may not look weird in some areas ... like a big full size 737 painted permanently on the runway because it was there taking off when the satellite imagery was taken. Others have mentioned the online bandwidth requirement might not suite every person's situation. I don't say any of this to discourage osgEarth or be negative towards it, just to try to help craft end users expectations of what it might be able to do for them. osgEarth can lead to some very compelling vistas at altitude, and I'm sure there are many other good reasons to have it available, no one has stood in it's way or vetoed it or even discouraged it's development as far as I know.
In the end, osgEarth needs to find someone knowledgeable at the graphics level who has the time and energy to port all the changes to flightgear 2016.2 and then be willing to entertain feedback from existing knowledgeable developers and make corresponding adjustments to their work so it can fit into the overall scheme with minimal disruption.
Here are a few more tips, and I know these and others have been discussed many times previously ...
It is good to submit patches in small self contained bundles so that people who would review the changes can manage to see and understand what is going on. Dropping a big massive change that touches dozens and dozens of files in significant ways is very very difficult to review. Developers do not like to be pressured to "just do it", "just commit it" ... we are all volunteers right? Some of us have a compulsion to understand what we are doing before we are comfortable doing it.
There are a very small number of people on the forum who prefer to be adversarial, but FlightGear has always been a good group of people trying their best with limited resources of time and energy, so please be patient, and don't feel bad about sending reminders if something isn't getting attended to as quickly as you like. FlightGear started in late 1996, early 1997 ... so that's 19 years if I did the math right? That's enough time for many things to change. Subject matter experts can come and go. Key/core developers sometimes move on, leaving a knowledge gap. People have kids, or get married or get a new job or go to school or have all kinds of major life changes that affect how much the can or can't contribute. No one is getting paid for working on FlightGear, we are all volunteering our time. It's good to be aware of that and treat developers with kindness and grace and understanding that time and energy can often hit it's limits in our busy lives. I was something like 27-8 years old when we started FlightGear ... do the math ... a whole lot of life has happened in the meantime. I got my master degree since flightgear started, 2 wonderful daughters have made their appearance, we are on our 3rd dog who is also awesome, we've moved twice, I have had several job/career changes. Among the flightgear family there have been births, deaths, weddings, new pilots licenses, graduations, and every other major life event you could image. We are all pretty normal people doing our best to get through life and meet all the challenges that come along on all fronts ... and there is just never enough time in the day.
The FlightGear project structure isn't perfect and some people have been critical from time to time ... but it is like any system ... it actually does work when everyone is cooperating, but it can also be pulled apart and damaged by people that want to do that sort of thing. Personally, I think that together (100's of developers and probably 100's of thousands of users ... download stats report 10,000 people a week downloading FlightGear) ... together we have accomplished something pretty remarkable. It's not perfect, we still have tons of things to fix and do, be still pretty remarkable for a group of volunteers that decided one day it would be a good idea to build a brand new open-source flight simulator from scratch.
At the end of the day, treating each other well (with kindess and patience and understanding) is by far the most important thing. That is true here on the forum, and true in our real world lives and families and jobs.