I'm not talking about who was right or wrong - they were both right and both wrong at various stages of the conflict, IMO. I'm saying that the evidence we see in the games indicates that geth cannot necessarily be "rebuilt" after being destroyed, because there are instances where geth subroutines are permanently eliminated - specifically, the quarians' attack on the Dyson sphere and Legion's death. If the geth could simply reconstitute themselves after the elimination of subroutines, why *wouldn't* they do it as a matter of course?
You can say that these details are only in there because of bad writing, but I (and Shepard) can only make decisions based on what I'm seeing in the games, and nothing leads me to believe that the entire species of geth can be destroyed and rebuilt later.
And IMO, part of the reason that Gerrel was somewhat reasonable and sympathetic in ME2 was that it was to his political advantage to engineer an acquittal for Tali - a conviction and a discrediting of Rael'Zorah's work would have hurt the "hawks" among the quarian military. Koris is an annoying pompous ass in ME2 for similar reasons - he thinks Tali and her father are wrong about the geth and is trying to build support for peace. It's not an especially flattering portrait of either of them, but they're hardly the first authority figures or politicians in Mass Effect to behave opportunistically. And Xen always seemed like a bit of a nut - Tali even says "you're insane" at the end of one of the ME2 dialogue choices.
But I don't disagree with Xen. She's eccentric, yes, but she's a scientist. She has her political beliefs. And she believes the Geth are machines. Tali believes experimenting on childhood toys was sick. Tali was such a gentle soul. Xen obviously more inquisitive, so she pursued the path of science and experimentation. Tali just gathered data.
They are going to need their homeworld for their people before their immune systems deteriorate further. I disagree with Tali. I disagree with the way the plot in ME2 was written. Why, for example couldn't Shepard have given the data recovered on the Alarei to Xen AFTER the acquittal? Because of built-in character stupidity to force plot direction, that's why. The clues are there laying in front of everyone, including Shepard, yet every single character acts completely clueless about it while you, the player have the entire thing figured out as to what is going to happen. Peace between the Quarians and Geth? Dream on. Your choice doesn't matter. Your influence doesn't matter. There is no conflict with peace. Without conflict there is no story. "Good luck in your war." Conflict = story. Who wants to read about peace and happiness? The story would put you to sleep. You'd introduce something like a bee sting to introduce a conflict. Or someone would fall in a well and Lassie would come running and bark. Conflict > Plot > Resolution.
"Admiral Xen, can we talk for a moment?"
"Commander?"
"Tali explained to me some ramifications of publicizing certain actions, but if they were to be kept secret, I might have some valuable scientific data for you."
"Really? I believe I could maintain secrecy. What did you find?"
"I think this data could save you a lot of time. It looked like Rael was on the verge of developing some sort of weapon. Just be careful with it."
*examines some of the data* "This is amazing. Thank you, Commander. Tali, rest assured I'll keep your father's name out of this. And Commander, as soon as I have something, I'll send you a little gift."
Timing. That may have saved about three months of development and they may have defeated the Geth before the reapers arrived on Rannoch. Smart, right? So you have to have the reapers arrive on Rannoch then. Or even if you had peace between the Quarians and Geth before ME3 you'd have to have the reapers arrive on Rannoch. Since the Geth uploaded themselves into the Quarian suits, you'd have the reapers hack the Geth code, and turn the quarians into monsters like the Zha'til, except for those like Xen who refused the upload. Conflict.
The admirals are stupid. Shepard is stupid. Tali is stupid. Legion is stupid. And the purpose of the stupidity is to force plot direction. Logic goes completely out the window. Why? Because to write a complex plot like this in a video game takes resources. You could have had an entire 25 hr game about this alone with half-way intelligent characters and an intelligent plot with the nuances. But instead you have a 3 hr overly simplified mission that forces the plot direction and has to use idiocy to do it. Sad, but well, it's a game not a novel.