I agree PC simulators are pretty dead genre now and this won't change in the future. I think what mostly killed them was emerging of console games market which removed PC from position of most popular gaming platform. On the other hand it is almost impossible to develop advanced simulators on consoles due to many various reasons. What is worse younger gamers play usually on consoles and PC games (especially simulators) look like some dinos to them!
In sum PC simulators market shrink considerably in the last decade to the point all mainstream publishers abandoned it with UBI being the last example. Now PC simulators are developed almost exclusively by fan groups and companies present on both military and entertainment markets. Such situation means game development takes very long time (fan groups do not have enough money, they write games in their spare time) or games are quite expensive and not always possess features liked by players. That is why you have only those still "active" simulators left:
- Steel Beasts Pro - 125 bucks only
- DCS study sims family made by ED - each module bought separately, lack of dynamic campaign, quite long development time
Maybe Oleg Maddox will make a show with his Storm of War but let's wait how this game will finally look like. Anyway MS abandoned FSX, UBI most probably abandoned SH franchise, Sonanalysts left game market after DW release, etc. I intentionally do not take into account some old games still sold or modded today because this is another story.
And that is pretty much all...