Alright...
Was the event railroaded? Of course.
As has been said, the event was not designed for us to win, period. Even if, by some miracle of the servers, we had all functioned perfectly and annihilated every single Revenent in system, would that have stopped the storyline? I don't believe so. We've even seen it happen before - in Ashab, when the first Revenent was destroyed (thus altering the storyline) a second Revenent was introduced, because at this point Sansha must succeed.
Is this something to act angry about? Well... if you're angry because you expected a chance to stop Sansha here and now, I don't think so. Do you really think CCP is going to push pause on content that's been in development for months, or alter their release date because we managed to pull off a miracle? I don't.
If you're angry because CCP is using this means of linear storytelling in the first place and you don't think it's a good idea... well, I personally think there's merit in that point of view, but that's not the discussion we're having here and I don't want to derail the thread (again).
Edited to clarify something: With respect to the Slave Endoma incident in Ashab, I'm not complaining about the second Revenent being deployed. To simply say "oops, have to tweak that... and go home now, little capsuleers" would have been, as someone told me, anticlimactic in the extreme. What upsets me about that incident is how (aside from a couple lines of text in local) the whole incident was entirely ignored. They could have done something with Vieve Creston coming on IGS or Synepub and talking about a special CONCORD detachment sent to engage the Revenent to search for new technology or something... again, would it have affected the storyline? No. Would it have been nice to have it at least recognized? Yes.