If you were to step back and take a look at the show as a whole, it is not that bad. The animation is breath-taking, the fight scenes kept me on the edge of my seat, and the characters were all loveable in their own way. My issue is that the story was pushed and stretched to meet the series end instead of taking time and having the characters talk about some really important issues.
[SPOILER WARNING FROM HERE]
One of my biggest problems was that the show really wanted you to get involved with the characters. Said characters would be allotted some time to get some development, and then it would jump to another character or back into the storyline. It was endlessly frustrating when some pretty important events would happen to a character but then the show would just move along. More important things to do, right?
Does anyone remember when Lance died? Oh, Allura does, and she brought him back. Hooray! But is it ever mentioned again? To the best of my knowledge: no.
Okay, so does anyone remember when Keith almost sacrificed himself to try and break the shield? Matt does, but it is never brought up again. So I guess I'll be running under the assumption that a) either Matt and Keith had a conversation about what happened off screen, or b) that Matt just didn't deem it important. Knowing Matt's character, the first choice is most likely, but it is never confirmed.
Does anyone remember in "Black Paladins" when Shiro tries to kill Keith, but Keith manages to save them both? Remember how Keith was willing to die just for a chance to get his friend back? But in season 7 and 8, Shiro just seems cold. They've gone from people who would sacrifice everything for, to just business associates.
To me, it's endlessly frustrating to see these characters go through such pivotal moments and then brush them aside. These moments were just to further the plot. Lance's death was used to further his relationship with Allura. Keith's near suicide was used to portray Lotor as some kind of hero as he swoops in to save the day, and unknowingly, Keith's life. Keith saving Shiro was just used to keep Shiro alive.
These were just some of the main scenes I can remember. Practically all of the characters (except for Pidge) had this happen to him. Hunk had practically no development, and many of the characters seemed stuck inside their archetypes. Lance as the lover-boy/comedic relief. Hunk as the stereotypical big guy that likes to eat. Keith as the emo kid. And Shiro as the admirable yet distant leader.
I don't seem to be misconstrued. These characters were given several moments where they were allowed to develop and grow outside of their shells, but then some the next episode, it seems that they would be back at square one.
I have many issues with this show. These were just some of my primary frustrations, and to go into everything else would result in a long and drawn-out essay that I am sure no one would want to read. I'll keep it short.
Voltron was a good show, for people who are interested in casual viewing. But for those of us who watch shows for the characters, I would classify it as a major let down.