I think my take on Primus and Unicron leans gently that way, unlike most all canons, they aren't aspects of Light and Dark, just two primordial entities of similar type, who may have even met before they had to bond with planets. Their life-paths have affected their personalities though, Primus hasn't changed all that much because he sleeps a lot but Unicron's life as a planet eater has made him rather harsh.

Ultimately though, I personally imagine that if given time, Primus would be able to talk Unicron around, but Primus in Cyber-bunnyverse is still a bit pissy about being effectively paralysed due to the energon draught the war caused on Cybertron (the draught doesn't harm him, because he personally got fed rather well while he was asleep by all the dying sparks during the war, but unless Cybertron's energy problems are fixed and some superstructure details that got messed up by a lack of reference to the original construction plans are cleaned up, he can't transform Cybertron into his body), which he puts the blame right where it deserves to be - mainly on the Decepticons because the Autobots as they are at the moment aren't the corrupt assholes who oppressed the 'Cons in the first place, so it's no use blaming them for things they didn't do themselves.

And yes, if he got a hold of Unicron's head, he'd have sharp words about Unicron not bothering to actually look at the Transformers (at their sparks, specifically) before deciding to rip Cybertron apart, then trying to take Cybertron as his new body.