Imagine something that's trying to be a sequel to one of the best mecha anime ever made, and instead of respect for the source material they just ditch every single thing that made the original interesting and charming. All the dope sci-fi elements gone, the robots have a mind of their own for reasons??? (I suspect it's because Evangelion was already massive by the time that came out and they just threw that in there.) There are no likeable characters and the protagonist especially pisses me off, the big twist with her is just nonsense, I'd argue Diebuster is less a mecha anime and more a magical girl anime in the most excessively dumb way possible.
Point is, watch Gunbuster, it still holds up super well, isn't very long and I maintain that it's the best mecha anime Hideaki Anno ever worked on, I genuinely rate it higher than Eva.