You make it seem that these changes were unnecessary and revolting. Just because they were frustrating.

Revolting is a strong word, but not too far off either. The changes were, if not unnecessary, quite damaging and harmful on the overall quality of the story. You can't deny that, apart from maybe trying to fit everything into 13 episodes, the reason for the changes was probably an overt sense of conformity to shonen tropes and cliches.

Sometimes, I wonder if Kodansha ever thinks "Why are they angered? 6 months is better than 1 - 4 years."

But yeah, changes are unnecessary, especially when they go out on the Plot. I think Isayama once said he was disappointed with the UR arc and told those to change it up. It feels like a whole another arc, honestly.

We're waiting for the second part of the season an additional six months anyway; personally, I think waiting one more year for a higher quality season is worth it.

I don't get why Isayama was disappointed with the Uprising Arc. A ton of his fans think it's THE best arc of all.

I think people dislike it because it doesn't seem to feet in a series about killing giants. 

AOT turned political.

I agree that most people who didn't like Uprising probably did not because it took the focus off the Titans, but it's my personal favorite because it fleshed out the world inside the Walls and how that society operated. I really liked how a lot of the characters weren't necessarily bad people, but trapped by their circumstances and then forced to do things that they weren't necessarily proud of.

We lost a lot of that complexity in the anime adaptation.

You can see it in earlier seasons too. One of the best examples is Marlowe. In the manga, while passionate, he expressed the willingness to compromise by acting like scum, just like the rest of the MPs, in order to get to the top. Furthermore, there was also his admittance that he wasn't going to kill the corrupt officers or anything; just make them feel shame for acting like "dogs that took a shit wherever".

God, I love that line.

Anyway, it showed that there was SOME sense of boundaries to his passion and methods, while the anime painted him as an uncompromising but naive extremist. They also took out Annie's philosophical speech about human nature, which was also a bummer.

As someone who works in digital media and editing, I can tell you a lot of reasons for trimming down stuff from source material is just to save time, keeping the stuff that is needed while getting rid of the stuff that isn't. Yeah, world-building is good, but when it completely takes the focus away from the source of the series (ie, Titans), it becomes tedious on its own. Barring the scene with Levi choking Historia forcing her to be queen, I'm much more satisfied with the anime than the manga. I felt it was able to get important story points across while still keeping the action scenes that people really watch it for, rather than 'dialogue dialogue dialogue dialogue FIGHT dialogue dialogue dialogue FIGHT etc..."

Not that I plan to watch the anime after RtS arc, but hopefully they will do the same to Marley arc, because boy was it boring rereading things we already knew while waiting for the MCs to kick butt

You took Digital Media & Editing? Thats cool. I am taking filmmaking classes. I do agree on that, it is better to get the story points across and get your action at the same, without doing long episodes of just dialogue.