Damn, I need to rant about this with company, so thanks in advance for reading. Spoilers ahead.
I have a (bad) habit of replaying these games on a yearly basis. There's mutiple reasons, the most prominent perhaps is the fact that up until the end of the third game, they are so engaging and fun, the stakes are always incredibly high and ultimately, your decisions really shape the world around you. Curing the genophage, saving the geth, destroying the collectors, defeating Sovereign - it's slop, but it's fun slop.
Then you get to Earth by the end of the games and everything starts falling apart. The "beam" between Citadel and Earth is suddenly called "the conduit" by everyone and there is no explanation for it, and it's not like there wasn't the conduit in the first game. At the very end, once the crucible is activated, nobody apart from Shepard knows what the thing does. Still, the fleets are all fleeing, including the Normandy, but nobody knows what's going on. That probably includes the players by that point.
There is so much more in between these examples, but I don't have the beans to go over all of it. It's just a fucking mess.
The whole concept of the Crucible is horrible, like oh yeah every ruling group of organics for millions and millions of years has progressively been building more and more of it but nobody at any point knew or knows what it actually does? And then it can just magically make every organic part robot and every robot part organic.
They should've just let you defeat the Reapers with Facts and Logic if you reconciled the Geth and Quarians. Ideally you'd also get bonus points for stuff like how you treat EDI and the AI living in an air conditioner in ME1, but it seems pretty obvious that they didn't know what the fuck the plot of ME3 was going to be until it was way too late so none of those decisions would have been carried forward.
I still think they should've gone with dark energy as climate change metaphor.
My understanding was they actually did have the whole thing planned out years in advance, but then because the original ending got "spoiled" online, EA foolishly decided that having the ending be a surprise was more important than having it be good, so they made them change it.
they also took the writer off of ME3 to do the stupid star wars MMO they made instead of kotor 3
ruined two series with one management fuckup
I guess it didn't bother me much because the outcomes were sort of wish fulfilment and the fact that the endings didn't really matter much to me because the game was over after the ending. Imagine if they had to continue the story after that, oh boy.