That's because
Yeah, I see what you're saying. I didn't mind Xemnas's because it wasn't really redemptive, it just explained some of his personal motivations. I thought when he referred to his "companions" he was talking about lingering feelings from when he was Terra/Terranort which he actively wanted to cast away but that part wasn't very clear to me. If he was talking about the Org. members then yeah, that's not remotely believable, haha. Ansem SoD's was just limp, he's completely overstayed his welcome as is, Riku has no reason to miss him and neither do we. But Nomura likes his villains so I think this was his attempt to give them some sort of poetic send-off.