Eloquently put (as Lump would say). This together with the rushed ending cutscenes left a really bad aftertaste. Whatever you do, on a moral level you can't win.

On my first playthrough I played a Tav who refused to have anything to do with the parasite - he didn't use it and did not "upgrade". Then the game forces me
into an alliance with the Emperor. I learnt the hard way that you could not refuse him. Reload. Ok. Cue the ending and I could not keep up my determination as the game effectively forces me to give in to the evil I tried to fight, either by siding with the Emperor (who I never found trustworthy at any moment, so why give him the stones?) or have one of your side turn.

I strongly dislike that there are no consequences to using the tadpole and even stuffing your head full of them and I strongly dislike that we are forced to
have a mindflayer with us in the end. Even worse if you plan to let Gale blow himself up. Then there is absolutely no need for anyone to become a mindflayer, but you still have to do it.

And yes, the parallel to ME3 is glaring, as nothing we did before the ending mattered. We still get the same choices in the end.
Destroy or Control/Synthesis.