DCS is a multi era aircraft type sandbox
The FM developed are the best than any other sims I have played
While I do only combat, I understand that people want also just to fly the aircraft, and do acrobatics. There is a market for this, even if you don't like it, they are part of the community.
I don't see why adding pure civilian aircraft would split the community, they are compatible in multiplayer, unlike the WW2 asset from ED. When you go play online, you go on your favorite type of mission, that's all. No one force you to do something you don't want to
Devs need money, doing a fully simulated modern aircraft is a long shot. Over a long period of time you don't have income, you release it, then the sells slowly reduce other time. But they still need to update it, meaning work, and that's why they need in the meantime to release other module. As stated by Wags, WW2 aircraft are "easily" done and the return of investment is better than modern jets. So why should LLC not do it ? As long as they keep updating the mig-21 and do other combat aircrafts, there is not really a problem
Remember also that people on facebook or on this forum do not represent the majority of the DCS population. Many customers just play offline, and are the silent majority