Because that's awful? Canonizing Destroy is one thing, saying that all the endings end up working just like Destroy is quite another.
How is that awful in comparison to actually having a ending that allows you to stay in the Milky Way galaxy and not potentially have to give up the entire Galaxy you were building and the races there in simply because, "Well some people might like to be hybrid techno-organic lifeforms so we have to build 3 potential games in one in every sequel until the franchise dies." and control is no different as it would require now having to explain why VI Shepard isn't saving the day whenever a new crisis arises, and like i said still requiring you to make 3 Games in one every single sequel that takes place in the Milky Way Galaxy's present and thereafter future.
It doesn't, you are actually saying. "I'm okay with killing this galaxy and them having to do a rewrite or entirely new franchise with the same name and some borrowed ideas but basically in another galaxy, aka Star Wars."
How exactly can you reconcile "Refuse" with an ending where we survive and somehow magically destroy the Reapers afterward?
(And yes, for me Refuse is the canon ending. It's the only one where I can actually stay in character as my canon Shep during the finale).
You'll note that I didn't, because you already have Andromeda, hint hint, its just as likely a ending that leads to Andromeda, also there is no need to reconcile it because everyone is dead. Basically its the same with ME2. If you let Shepard die at the end of ME2 (no one pulls them on to the Normandy) then that was the end of your ME Saga, you now have the option of not playing ME3, Reapers win same outcome, you can now play ME4 and feel that your story is still canon you are now simply playing a entirely new game. If you played ME3 you already are accepting that you aren't playing your original ME2 Shepard who you canon wise let die, if you choose refuse in this one. like I said you have Andromeda no need to reconcile anything.