Again, where is this hate for Black Panther coming from? I thought it had an interesting and compelling storyline, great settings, good fight scenes, well-developed characters and a complex villain. What did you find bland about it?
I don't hate the film, not in the seething way I hate Ragnarok, it's just not enjoyable for me. As for what I find bland, for me, it hinges on the characters. That's what I tend to focus on. Particularly T'Challa himself. To me, he's as wooden and one-dimensional as Carol Danvers (though, I can pick Carol apart more than I can T'Challa) and could have used some of his anti-hero tendencies from the comics. I walked into the theater wanting to like him, I liked him okay in Civil War, but then I just found nothing in his character. No significant internal or even external struggles until late in the film. He seems to have done any growing he needed to do in Civil War and, for me, that leaves his character kinda flat in Black Panther. I enjoy the deeply flawed and even very broken, emotionally or physically or both, characters of the other films who have to build themselves up. T'Challa's just not doing much for me.
As for other characters, I found Shuri forced and kind of annoying without much depth similar to T'Challa (and as of Infinity War, I can't stand her because she was mean to Bruce and that's an unforgivable crime in my book). The girlfriend, don't even remember her name is- nice, I guess? Maybe I'm not remembering well enough, but she didn't seem to do that much. The only one I really enjoyed was M'Baku because of how boisterous and fun he made his few scenes, and even then, I don't find myself caring for the character in any lasting way. As for Killmonger, frankly, I just can't get myself to care. I can appreciate his motivations, though, I think the whole killing children thing pushes him beyond the pale, but I wouldn't count him as much better than any other mediocre MCU villain. None of these characters really spoke to me in the way something like Guardians really did. Maybe that says more about me than anything, that I prefer casts where there's a whole metric ton of baggage to go around.
Wakanda as a whole was a pretty neat setting, though, I thought it was underutilized with much of the conflict arising from outside of it. The opening scene, I remember laughing at it in the theater because of how cartoonish the whole "I'm on your side, but wait! I was actually on his side the whole time" thing was. As a whole, not a particularly memorable or fun watch for me and not something I'd care to watch more than the couple times I have.
All of this is subjective of course, and certainly don't let me stop you from enjoying what you enjoy. Ultimately, I'm just not into it the same way I am other movies in the franchise.