“They had to kill Loki so Thor could finally take center stage in his own franchise!”
Uhm… listen, if you have to kill literally everyone and everything from a franchise – because it’s not just Loki, they also killed Heimdall, Thor’s friends, and the Asgardians – just so no one can outshine your hero ever again, then maybe you just did a bad job at making that hero interesting in the first place. (I’m not saying Thor’s not interesting, I’m just saying this reasoning makes no sense.)
Also, since when is it a problem when another character’s more popular than the main hero? That happens all the time? The main heroes of stories are almost never my faves, so what? Why would you need to punish your audience for liking another character? Doesn’t it make more sense to give a character a bigger part if the audience likes them instead of limiting their screentime and senselessly killing them off because “the audience’s supposed to like that other guy”?
Sorry, but that is exactly what happened in the comics from what I know, so this was always the plan. And there’s a part two, remember that.
I haven’t read the comics, but what I definitely know is that these movies already aren’t faithful to them, so I’m not expecting them to be, either. Many of the MCU characters have completely different personalities and motivations from their comic counterparts. For instance, comic!Loki was a full-fledged villain at this point, while MCU!Loki has spent the last few movies somewhere between anti-villain and anti-hero and is a hero now. These movies are supposed to be good and make sense outside of the comic books, and that’s how I’m juding them.
And no, this wasn’t “always the plan.” Tom Hiddleston has recently said that Loki was originally supposed to die in The Dark World, and they only filmed that ending-scene where he turns out to be alive because the test-audiences didn’t believe he was actually dead. Marvel’s been trying to kill this character for a while now because they just don’t seem to understand what to do with him.
And yes, I know there’s part two. That doesn’t mean I can’t feel disappointed about my fave only having three minutes of screentime in part one, and getting killed off before the title card even appears, while every other character got to interact with each other for a whole movie and do some badass stuff before dying. (Do you have any idea how long I’ve waited to see Loki fight alongside the Avengers? Yes, I feel cheated I didn’t get to see that!)