Well, Cortana did say something seemed strange when they found out where the signal was coming from, and she was hesitant and being all "this doesn't feel right" when the Chief was about to activate what turned out to be the thing to release the Didact.

pete_the_duck:
: I've always felt that Cortana and the Master Chief are incredibly gullible in
: Halo 4. 343 had to figure out some way to release an ancient evil--and of
: course the Master Chief must be the one to do it--but really? Who puts a
: communication relay at the center of a planet, and then surrounds it with
: shields and suspends it over a giant blender? Derp.

The Forerunners did a lot of hard-to-understand things.

Avateur:
: What makes you think that? By the end of Halo 3 it's estimated that
: humanity's total population is 300 million. That's not just referring to
: Earth.

How do you know what it refers to (or if it's even still canon >_>)?

: The entire way the part with the Composer is presented in game is
: completely removed from its impact and also its consequence. Where is the
: Didact firing? Did he choose that place for any particular reason? Did he
: just decide to blast away at Earth? How populated is New Phoenix? Did he
: kill twenty people? A thousand? A million? Does the beam spread out the
: more it hits? Would he need to just swipe the ship around the Earth
: endlessly to make it kill people? And even then, how many of that
: approximate 300 million are even on Earth to kill? And how many are even
: in America, where he's targeting at that particular moment?

um, what? Why are you still talking about 300 million? It's been over four and a half years, I'd think it changed a little (most likely it increased).

: He didn't really begin to exterminate anything and the threat was never felt,
: especially since the Didact himself was such a paper tiger and the
: Composer literally got nuked. Boy, that was difficult. The entire
: execution of the so called threat to Earth and humanity in Halo 4 was a
: joke and was really never felt. Nothing was ever at stake. 343 Industries
: never had the balls to really do something in that game aside from maybe
: sort of kill Cortana, give or take space magic and a lot of bullshit.

I agree the threat wasn't felt for a lot of the game, but...

: Chief technically died and space magic saved the day, but sure, we'll go with that.

what? how, when, where... I don't...

: But oh no, not the Ivanoff Station!

Are you telling me it didn't get to you seeing Dr. Tillson get disintegrated?

: And what? He's done his share of damage to the Earth? What'd he do? Blast a city
: for a little bit and kill some untold number of people? Again, how many? I'm sure
: 343 will come out and say that some horrible unimaginable amount were killed at
: New Phoenix just for impact's sake since the overall impact is still to this very
: moment completely absent, but for all I know the Didact blasted a few people.

I don't think it really matters how many people were Composed. One is too many, right? and we can agree it was more than one? more than 5 or 10 even? I think that's enough.

: Hypothetically speaking, let's pretend Forward Unto Dawn never wound up at
: Requiem. Well, apparently Infinity in its cosmically brilliant timing shows up
: there right as some crazy stuff is about to go down. Hypothetically it shows up
: there regardless of whether or not Master Chief does.
: [snip]

From here to the end of your post, you mostly have points I agree with, so I'll just cut it and say that.
I don't know, I agree there were flaws, some of them serious ones, with Halo 4's story and how it was presented, but it sounds like you're mad at them for doing a bad job of writing, and it's starting to seem like, to use an example, picking on someone for being clumsy when they have cerebral palsy or Parkinson's disease. Maybe it's because it's happened so much lately, maybe it's because I can sympathize so much with having trouble with writing, I don't know. I'm not trying to defend 343i because of any of that, in fact I'm not specifically trying to defend them at all. I agree they had a job to do (or several) and failed at it (or them) varying degrees. I just felt you missed some things in what you said, and I had a realization about how I felt about the whole thing and wanted to share it.