Redemption arcs aren't bad (reddit is just filled with absolutist shitheads), I just think they have to be careful in how they use them (since the audience is commonly children to these types of "redeeming the villain" arcs). For a show like SU that built up a such a huge villain like the Gem Empire it was honestly weird to see them turn it into a family drama of generational strife and misunderstanding, i.e. I feel this is a lib style of the show alongside the treatment of Bismuth as you pointed out. Then again it's weird having a show that's legit set during a lull period in which a revolutionary force got more or less killed/PTSD bombed by a nuke and the evil empire has continued to blow up and exploit planets as colonies. It could be they rushed it, or didn't know how to properly conclude it once the set up was done on Homeworld. The show may have been better off set up in a higher age bracket but then again that stuff is never greenlit by studios so what was made was already pretty amazing by the standards of children's entertainment at the time.