Yes, there is that thing about what is a core feature. Most single player games do have multiplayer included, and I now think it would be better if Stardock took a bit longer and made a SP-style co-op mode with as many features as possible from SP, and only leaving things out if it was tried for a decent time frame and didn't work out. But certainly not "Quests are too hard, ditch them. Tactical combat too hard, ditch it." People are still playing AoW:SM since 2003 and it has Quests and Tactical Combat in MP Co-op - and you can have MP-Competitive in the same game. Are you saying you can't beat an 8yo game with the resources at your disposal? It is just a mindset/ideology which you can change if you really want to.
Most software developers do not have the luxury to try implementing features to see if they work, and when they do, it is usually only in the form of exploratory development. In general, this is just not feesible option as any feature that does not "work out" is a significant production loss and could jeapordize the entire prodution. To make it as simple as "Quests are too hard, ditch them" does no justice to what is being actually produced. If SD was saying that Quests were too hard to implement well so they are removing them from the entire game, it might be a different story. However, this is not the case at all.
Good point. You have informed me on some aspects of games software production that I did not know before. Thank you. 
As for you points about AoW:SM, it is always funny to hear people compare the two games, as beyond the surface experience, the two games are fairly different. With the exception of units and tactical combat, Elemental is a far deeper and richer experience in every way. Quests in MP AoW are heavily scripted static experience and are not even remotely close to the dynamic quests available in Elemental. In general, the entire AoW series had one focus for the player which was the tactical combat, and every other system is shallow, pushing the players towards the one focus which is the war game experience. Elemental has a rich research system, city management system, diplomatic system, unit customization system, quest system, etc. While these system may be far from perfect, each one has a depth that AoW:SM does not. Play a game of pioneers only in AoW SM and tell me how rich the city building game is. Wait, that right, the AI won't build new cities at all. The only advantage AoW:SM really has over WoM is simply that the game is incredibly focused on one specific experience and each iteration of the series only added mechanisms to attempt to deepen that one experience.
You make some good points. And I haven't played much AoW:SM, just enough to know there are Quests and Tactical Combat in MP. And it is true that the Quests are fixed (always the same in every map, including locations) in AoW:SM whereas they are not in Elemental.
So what do you suggest for the MP problem, especially given Alstein's comment?
Best regards,
Steven.