^Not sure how you expect a "successful refuse" to play out. The Reapers cannot be defeated by conventional means. This has been made abundantly clear since ME1 and was practically hammered into our skulls in ME3. Everything was riding on the crucible being the solution, without that, all there's going to be is a slow grind into extinction just like every other cycle.
Of all the issues I have with the endings, this isn't one of them. I actually liked how they implemented the "refuse" option in the EC.
That's why I said "somehow"
Never said I expected it to be conventional. Let's be fair, you could have gone for an ID4-style virus ending and it wouldn't have been any more ridiculous than the ending we got anyway. The seeds for an unconventional refuse could have been sewn throughout the game. I'm still not sure why they didn't do this, considering that the way the ending was written your choice depended entirely on swallowing what the enemy CiC is telling you. Clearly no lessons learned from your experiences with TIM in ME2. Shepard doesn't even bat an eyelid when she/he's being told all this stuff. That's where the character breaking begins. It's akin to buying Saren's rhetoric in the first game, taking it at face value and deciding he's right. Would have been a short trilogy.
It's lucky that I can tolerate the Destroy ending, but even then, Shepard's blind trust still grates. There are plenty of other reasons to loathe the ending though, Lord knows it's not like all those reasons haven't been debated ad infinitum over the past couple of years!