It cuts both ways. Yeah SP can feel scripted and the bots aren't always a good challenge, but in mp you have to be in a match with pretty skilled tactical players, or they can look just as dumb if not worse than the AI. Then you also have players using hacks, exploits, etc, or just playing for themselves more than the team. MP can also get repetitious with same old objectives and tactics over and over.
I'm surprised you'd mention CoD if you want realism, because lately the movement, aim, animations, reload time, recoil, pretty much everything, is very arcade vs real.