That was hard enough to organize under a single MA, with 150 or more pilots per country. Under multiple arenas, with caps, it is very hard to organize a mission against strats to effect the overall war front on a map.
Its rare to see a enemy strat factory knocked down unless it is very close to a friendly base. Combined efforts to destroy strategic targets across one or more bases are rare. Warfare conducted against material resources just doesn't happen much. Even HQ raids have dropped off from what I've seen.
The need for missions and strat attacks went out with the incoming of the "horde".
Why setup a mission when 50+ planes all fly and swarm a base anyways ?
Why hit strat ? it useless ... with 50+ planes moving from base to base, there is no need .
And lastly ... I would say the about 90% have no clue as to how to "work" the current strat system to their advantage.