the reason for me for flying 100% online is to share the expereince with other players (and some of them became friends over the years in IL2) on VoiceComms !
Its not the AI, i flew mostly COOP wars (who else would fly all the 16 B-17s in a 1944 scenario over germany or the B5N over Pearl

), its just so that after a few minutes alone in front of PC screen in a cockpit i am bored to death.................
But flying in a Bomber, 150km to target and 150km back (if possible

) with guys on comms flying other bombers and escorting fighters - that makes for me a good mission.
Its the men, not the machine - as 'someone' said in the past, even when ment in another meaning, it fits for me in CombatFlightsims
A very important point is that 1C has to enable the community to MAKE the gameexperience. That is mostly the FMB (working and documentation). A few days (if not from the very first) the Hyperlobby was full of IL2 COOPs in 2001. It sure had its faults, but the gameexpereince was there !
CoD is leaving the most players here alone IMHO. I dont build mission in the moment with CoD , and that after building hundreds of missions in IL2 the last years

AND, it enable a lot of people creating singleplayermissions and campaigns. You just have to check sides like mission4today many people build missions with IL2.
Adi_Galland (head of Desastersoftware) summerized it in the german ubi form quit good: the way 1C decided to make the FMB of CoD has reuced the amouint of people able to build missions in CoD a lot in comparison to IL2.
At least it lacks documentation and who can be sure that now made expereinces (mainly with this script system) in the FMB are still correct after a few patches ?!
btw, RoF has a very similar proplem i think, a very complex FMB - but at least it has a documentation (but i dont know how good this is !).