Why the ending did not work (repost)

This is a repost of an analysis I made about the ending of ME3, which of all my countless posts about that topic, I re-post here because it summarizes my view of things best in a relatively short piece of writing.

This is a summary. The problems mentioned here triggered further debate in the past, but at this point it may be beating a dead horse. In any case, this is how the scenario presents itself to me:

1. The In-world perspective

You are Shepard. You have reached your enemy's hq. You're at the end of your strength and you're injured, but you are, at last, confronting the enemy you've fought against, knowingly or not, ever since you saw Sovereign lift off of Eden Prime. This enemy is killing your civilization, and it has been killing civilizations for at least 37 million years. Apparently it can take images from your mind in order to appear as this boy. It tells you a lot of stuff about organics and synthetics. Maybe it's true, maybe not, but well, this is the enemy. Do you trust it?

Of course you don't, but that leaves you with a dilemma. You have no information about how to proceed. The enemy is in control of the situation. For all you know, pushing any of these buttons will just kill you. Why doesn't the Catalyst just kill you? No idea, perhaps it has no physical limbs or servants up here to do it, so it has to stall for time. Anyway, everything it tells you is suspect. Normally, you'd be looking for the fourth button it hasn't told you about, but there isn't one. Well, of course it could all be true. Your theory of mind will probably fail with a million-year-old AI, but would you bet your civilization on it?

It doesn't matter. You have no single piece of reliable information about how to proceed. All you know is that this thing has been trying to kill your civilization. You might as well throw dice to make your decision. You're caught in an inescapable infinite suspicion chain. So what do you do? As the player, you take a step back. You leave the in-world perspective and switch into the storytelling perspective. And now the sh*t really hits the fan, because all the thematic and narrative inconsistencies you could ignore in the in-world perspective swoop down and explode in your face.

2. The storytelling perspective

....because now it is driven home what this situation really means: there is no hero's solution. There are only the antagonist's solutions. It is in complete control of the scenario, and you have no way to break it. You have no meaningful agency since all the choices are predetermined by your enemy. The reasonable thing to do, given how stories work, is to refuse to take part in this game. Of course we all know how that ends, and actually the story seems to assume you should become part of your enemy's scenario. But that *would* mean that the Catalyst wins, not you. This goes for all the main choices: Destroy destroys all the synthetics. This uncomfortably associates with a Reaper method: genocide. Control will make you - or something of you - into an AI god and take control of the Reapers. This uncomfortably associates with another Reaper method: indoctrination. Synthesis will ultimate fuse organic and synthetic life. This uncomfortably associates with yet another Reaper method: Reaperization. No matter that this is - rather obviously - not how it was intended to come across, this is how it *does* come across on the associative and thematic level. If you take one of the three main choices, the antagonist's values are ascendant, and you have lost - lost in a much more profound way than losing your life.

There is more, though. Suppose you can ignore that and listen to the Catalyst without rejecting what it says because it's the enemy and you have no reason to assume it wouldn't deceive you. Suppose you decide to listen with an open mind. Now we are facing a different problem. The Catalyst asserts a problem. If you were mostly paragon or neutral, you have been playing a story that emphasized again and again that we aren't doomed to conflict, that we can build a good future if we can overcome our prejudices and work together. For 2.9 games, you have been pestering people for co-operation against a common enemy, for burying old hatreds, forget past wars and work for the future instead, and you have been rewarded with significant changes and very satisfying outcomes. This has worked even between organics and synthetics. You have started to understand the geth and made peace on Rannoch.

These things have narrative weight. 2.9 games of narrative weight against the assertion of your main antagonist? And you're expected to make one of three choices, all of which are presented to you in the context of the truth of this assertion? How does this not come across as insane? So are you supposed to disbelieve it? If so - yet again - why isn't there a fourth button to press and make you win? Or is this a scenario where you can't win? Well, yes, on the thematic and narrative level, this is a scenario where you can't win. Even if you would really like to believe that at least one of the main options is a good one, on this level the story tells you that (1) the scenario is flawed, and (2) all the options are the enemy's options.

This is why I've said it's best to treat the Catalyst encounter as a black box. Somehow you get the information about what the ending options do, and you can choose for the future you prefer, and/or avoid the downsides you find least acceptable.

3. Is the Catalyst encounter real?

The hypothesis that the Catalyst encounter isn't real has some merit. In fact, at times I've thought that it took place in your mind and you were making your decision as you were dying, and that everything after your collapse at the control terminal wasn't real in a physical sense. That would explain the symbolism of the choices neatly - in the associative realm of your mind, you could trigger a meaningful choice through a symbolic action.
You know what, though: it doesn't matter. Physically real or not, the Catalyst has complete control over the situation, you are in its game with no way out, and the consequences of your decision are real.

Conclusions:

The ending choices present interesting alternatives for the future of civilization. They have certain intrinsic themes you may or may not find appealing, but in and of themselves any of them could make for a good future. However, their presentation through the Catalyst encounter means you either can't believe in any of them, or they're narratively tainted by being the antagonist's solutions, or both. Thus, the Catalyst encounter, not the ending choices themselves, is what makes the ending problematic.