Can someone help me understand the Tamlin love lately?

As someone who has finished the whole series, I've seen a lot of support for the idea of Tamlin getting a redemption arc, and I fully support that. But canonically, Tamlin is the reason that Rhysand's mother and little sister were killed, no? So while he's not a character I think never deserves redemption, I kind of...understand...Rhys' virulent hatred for him?

To be clear, I'm not a huge fan of Rhys, either. But sometimes I feel like I'm missing something when people go on about how Rhys should have forgiven Tamlin by now. If you mean just for his treatment of Feyre in MaF then yes, Tam definitely redeemed himself by saving her from Hybern/bringing back Rhysand from the dead. But I find it reasonable and realistic that Rhys can't get over his hatred of Tamlin when Tamlin told his father and brothers the location of his mother/sister, knowing they were going to kill them.

Am I missing something about the circumstances of Rhys' family dying? I just feel like it's never brought up in the Tamlin defense posts, and it seems like it would be a massive cause of the ongoing enmity between Rhys/Tamlin.