That is still poor on Bioware's part. I dodn't mind the crucible aspect of the game, what I disliked is Bioware inttoducing a non-sensicle character in the last 5 minutes wirlth flawed circular logic. The starchilds excuse is easily debunked just by my characters actions alone. On top of that I should have the option to destroy the reapers without needing to sacrifice the Geth, EDI and myself.
The broken promises and massive plotholes nearly ruined videogames for me.
Not that you're entirely wrong... but here's how I think of it now.
The Starkid isn't really a "new" character as he's the AI created by the Leviathans that initially rebelled and his presence and will were in place directly and indirectly in all three games, through the Reapers and Collectors. He is Sovereign, and Harbinger, and every Husk and Cannibal and Harvester... extensions of its will. He's not a singular character so much as he is just a glorified AI networked to all the other Reapers and his "form" of a kid is only assumed to mess with/calm Shepard. It could've taken the form of anything, and it chose the form of the kid to best connect to him.
Now, here's the thing though. His circular logic is absolutely flawed... by DESIGN. That's the problem with him. He's not human. The DLC with Leviathan affirms this; that the AI glitched. That its reasoning is inherently faulty and thus they could not reason with it themselves. They screwed up when creating it and thus logic that works with people fails with it because it inherently disbelieves that nature and organics can change, even if you reunite the Geth and Legion. Its conclusion is this alliance will not last, and it cannot be swayed.
It's not all-knowing. It's not perfect. It's a rotten AI that doomed its own creators and brought horror to the galaxy, based entirely on its own delusional circular-logic. YOU exist because it is itself incapable of breaking free of the cycle, thus giving you the weight to do so on its behalf. It's still constrained.
Now, I still hate the "space magic", and I still hate that "Destroy" robs you of the Geth and EDI (it really does make no sense, I won't argue, and mentally I sort of always put them right back in). But even if you accept that EDI and the Geth were physically destroyed, there's enough wiggle room there to argue that they still endure. For starters, the statement "everything that was destroyed can be rebuilt" by Hackett, and EDI was the heart of the Normandy and in charge of certain vital systems, thus the ship shouldn't function if she was entirely destroyed, while the Quarians mention that many Geth uploaded their consciousness into the Quarian suits themselves and it's possible the energy blast merely destroys their physical platforms and not their collective networks.
It's some mental gymnastics to be sure, and Bioware did screw up making the loss of all AI some arbitrary part of the "destroy Reapers" solution (basically forcing you to pick between your character or EDI and the Geth), but considering their very nature is so vastly different than the Reapers, and VIs are necessary for lifesupport systems of various ships and those endured just fine, I give myself enough mental leeway to allow for the possibility of their survival - regardless of Bioware's intent perhaps.