Kitsune - That's not a very good argument, what is SC in general if not tedious? Econ is even more tedious than war and if that is something people aren't interested in, then the game wouldn't even exist.
That wasn't the problem, otherwise people would have never learned how to level up or take c3's effectively or how to get #1 FI ranks or using ASQ's in corps or debt bombing or cornering the soy bean market or naming every one of their 1500 CEO corps or...you get the point. All of those things are tedious and require a lot of clicking, but they are all things that you and many other players do. The biggest problem with war is that it involved a lot of risk to learn, I had my first two empires on FB wiped out completely for example. As people became more attached to their countries due to no longer being able to completely strip out c3's, then subsequent changes that made stripping even more difficult/less effective ultimately led us to the situation where there is no war, with most people in WP and war being treated as an abhorrent action when it used to be commonplace and fun. Of course the war levels haven't made fighting more interesting for you yet, nor probably anyone posting in this thread, as we all know how to take out a country with 6k ints and 50 forts with standard c3 garrisons, but when it becomes 80k ints and max forts everywhere with no nukes allowed and 15K km away from your country and it's to score 50 or 100 GC? That's interesting...add on to that the country fighting back, once again, interesting. Lots of strategy involved, lots of challenge and a way to compete with others, all without having to risk your country if you choose not to.
Another big problem is/was the time it takes to fight wars, this has been mitigated somewhat by the introduction of 8 hour blackout periods although not eliminated completely, but really, there is no way to eliminate that issue completely unless you go the LG option and just eliminate war completely...
As far as how this will bring back federations, the following:
Brings in/keeps more players
More players interested in war
Players want to learn effective techniques to war level up just like they have always for regular leveling
Players seek out federations to share such information
Also:
More players interested in war
Players interested in defense and strategy
More players interested in federations
Pretty simple.
EDIT: Also, saying that the problem is that it is too tedious ignores the fact that it used to be wildly popular...lots of people played the war game, quite often and quite actively. The system itself hasn't changed so that can't possibly be the reason.