I think, some people truly fail to grasp just how bad the ending was. I feel like they don't see the full scope of how the rest of the story was retroactively shat on. Take for example this scene from earlier in the manga. It's explained how Eren first came to the realization that the titans were stealing his freedom, and how that hatred of his was ignited. But then 139 comes along, and it turns out Eren killed his own mom. Led to smiling titan directly to her so she could get chomped. Why? Oh, to motivate Eren and make him hate the titans. But with pic related it was already established that he had long despised them. The damage ch. 139 had on what would have been a great series can not be overstated