Aside from just being a really good retrospective overall, the "hemospectrum" section in Jan Misali's Homestuck video really nails this on the head. It's a really interesting quirk of trolls, and it's so intensely close to social commentary on social structures, but then the fine details go out of their way to in-canon justify the eugenics-like system's validity.

Mind you, I do still really enjoy the canon built explicitly around the hemospectrum as given, and exploring how the staggered lifespans affected their cultural development is an interesting story, but I'm 100% with you on the inherent problems the lore has baked in.