Im sorry to say that, even though I realise you're angry for the initial ending, some of your statements are simply shortsighted (probably related to the rage).
You state: "[the] ending based around the assumptions that synthetics will eventually kill all organics even though I spent 3 games proving that little retard wrong."
It's true that, especially in the last game, a lot of AI's are shown as good things. Unshackled EDI that falls in love, Geth that mourn for the deaths of their creators during the initial outbreak. However, this is a simple plot device. Sovereign, Harbinger and all other Reapers assume technological singularity is inevitable. To be honest, I think that -in the long run- it IS inevitable.
However, The Commander single-handedly proves them wrong within Mass Effects timeline. Like I said, the Geth mourn and EDI emotes. It proves that the Reapers are some limited kind of wrong and that this cycle is finally ready to surpass the cycle. The Catalyst understands this, therefor it does not stop Shepard.
You state: "Did you all forget that the existence of starchild practically turns the entire plot of Mass Effect 1 into one giant plot hole? Why did Sovereign need Saren to fix the Citadel signal if starchild was always there? How did the protheans manage to sabotage the Citadel if the starchild has the ability to get into your head?"
First of: It doesn't matter if the Starchild can indoctrinate or not. It respects the attempts to end the cycle. It doesn't stop Shepard. It even allows Shepard his own choice to determine the fate of the universe to a limited degree. It's also never stated that the Starchild controls the Citadel. It lives there and it's activated by the Catalyst. However, it's not in control of the Citadel.
It is possible, however, that the Starchild asked Sovereign to activate the signal again. Sovereign (and the other reapers) are each concidered Gods, so the mission could not fail, but it did. In the final battle in Mass Effect 1, where Sovereign was in direct control of Saren (the way Harbinger took control of certain Collectors), and Saren was destroyed by Shepard (a thing Sovereign held impossible), Sovereign lowered its shields and the Human fleet destroyed Sovereign.
This caused the Human race to catch attention of the other Reapers, amongst which was Harbinger. Harbinger is the commanding force behind the Collectors; the synthesized / husk-like forms of the Prothean. They instantly turned their full attention to the Humans. The Human Reaper was supposed to be the final answer to Shepard; until it was discovered prematurely and destroyed, forcing the Reapers (including Harbinger) to travel to Sol the hard way. By simply flying there. It took them a while, but they could finally strike their wrath upon Humanity (and Shepard) where it would hit them the hardest; Earth.
But again, Shepard can overcome this, escape, defeat the Reapers by using the Catalyst and controlling / destroying (or the other options) the Reapers.
It's not as "off" as you make it think it is.
