It's a sliding bar with realism. You say it's out of the window but I don't see flying pink elephants. Likewise there's a certaim level of believability and there has to be, hence weaponary loadout, player running speed, building scale, environments, etc.
RC Cars was an experiemental thing and they were actually made (should never have been a main killstreak, but assigned to the Care Package where Death Machine and Grim Reaper were found). In fact, the frequency and regularity of their threat was the absurdity, not their existance in a game based on 60s/70s black operations.
Tomahawks taking down helicopters was a game physics glitch that was never amended. Tomahawks in general were BS over a range beyond 5 metres.
Walking tanks? Never seen them in a COD that has been released. If you mean Black Ops 2, I think you cannot make any valid point on that until game context, actual mechanics and so on have been experienced. It is set in the near future and you are aware of robots, right? Treyarch have continually stated that the technology is already here and this is fiction, not science fiction. It's a possible future, even if it isn't a likely one. The lack of likeliness is to do with the WW3 scenario being played out to motivate such technology.
Ps. Just think of the technology involved in you playing COD online, and then conversing with me now.
Dual-wielding Mac11s is a bit of an OP issue. I've seen a ton of dual-wielders of machine pistols and SMG's in the movies, the problem is while physically possible it's inaccurate and inefficient, even dangerous in a multitude of settings.
So, that's the realism over. COD is not real and many things are far from it, but that doesn't mean using a lack of realism as free licence is going to justify anything or make a game better. Stealth Bomber on your own flag is unappealling for me, and that's why the damage counts against the player using it (even if on core modes the team is immune to damage).
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