It is much harder to create something like Ofp/ArmA, than it is CoD/MOH/Misc franchise.
And
So? It doesn't change the fact that ArmA is basically just OFP with 'new graphics' and a new setting, everything else feels totally the same like the 2001 OFP. And looking at those screens of ArmA2, while personally I think it looks good, it still seems to be essentially the same and more like an ArmA 1.5 and not like a new game, as you'd expect from a full game price
Is exactly what I was talking about when I said you need a different approach when judging a sim.
The IL2 franchise for example.
IL2 Sturmovik - 2001
IL2 Sturmovik : Forgotten Battles - 2003
IL2 Sturmovik : Ace Expansion Pack - 2004
IL2 Sturmovik : Pacific Fighters - 2004
IL2 Sturmovik : "1946" - 2006
All of these games are very similar, as is my understanding there were some big changes between IL2 and IL2FB, but aside from that - graphical improvements, more content (new planes, new theatres etc), then perfection of the aircraft and fine tuning of the already successful formula. That is the approach you take with simulations...you're not looking to dazzle, you're supposed to be representing. The better a representation you have, the better your simulation is. I don't know anyone who plays IL2 who has gone "ah well xxxx is basically just xxxx with 'new graphics' and a new setting, everything else feels totally the same" - and I can assure you, they do feel the same.
Now compared to your average Action FPS title, OFP/ArmA have destructable buildings and plants, AI controlled wildlife, conflicts involving dozens, maybe even 100 units at a time and a much vaster freedom. Not to mention the tools given to the community to create their own content.
Operation Flashpoint was a landmark title. The only title like it, and the only one really like it since has been ArmA. And, I agree that ArmA is OFP with visual improvements and a several features addressed. But that doesn't make it bad. Bohemia have clearly been trying to achieve something that no one else (until CM took on OFP2) was trying to do.
There is no point in comparing changes between an action fps + sequel, and a simulator + sequel. They aren't similar, and they aren't trying to achieve the same thing.
So, CoD4 is the #3 most played online game (I'm assuming you're looking at GameSpy stats), but the #1 online game is Counter Strike, and #2 is Battlefield 2.
And both of those are pretty mediocre. Why should CoD4's inclusion in that list make it more valid? Since when has how the populous reacted to something been a measure of how good it is?