Morale is way more important than most people think it is. When people lose morale, they just start sitting behind cades or sitting in the Alamo during FOB sieges.
If someone gets fracced by a lurker despite 3 teammates shooting the lurker, their morale is gonna tank. Same thing for getting hit twice and getting IB. The longer any round goes on the higher the chance of morale tanking events occurring and the more marines who are going to be just not caring about winning, just wanting to move on. Same thing with getting bad luck hugged and having to spend 15 minutes getting shipside and being blacked out with 0 RP at all during surgery.
I think the point youre missing the most though is Intel. Updating the Tactical Map pretty much as soon as it is avaliable is a must. If you neglect tacmap updates players split up and die in small groups which just accelerates other players splitting up and dying in small groups.
A D-tier SO that isnt that good of a leader or communicator can easily become an A or B-tier SO just by updating the tacmap every five minutes while the rest of CIC is neglecting it