It isnt that Kaine feels that Ben is bad but he is disappointed in him. In the limited series with Kaine as Scarlet Spider it was pretty clear that Kaine was trying to live up to who Ben had been, and the guilt he carried. Now Ben is back, isnt the whiter than white soul Kaine thought he was after the torture he went through, but now he is cured of clone degeneration after Kaine went through years of agony, only to be cured and now have a less painful version of it come back. Ben of course has a terrible experience, goes bad and then seemingly is returning to normal.
And Kaine who has always felt inadequate ever since the Jackal cast him out, he cant bear it.
And it isnt that Kaine hates Ben... its the opposite. He loves him and to see what Ben did as the Jackal rocked Kaines ideals and belief in how he could earn his own redemption. In fact it seems Ben says he can be redeemed and he gets the lucky break. Kaine has to fight every bloody inch for what he gets.
What Kaine doesnt get is that the torture Ben has been through since he died in PP75 has possibly been deeper even than the years of pain Kaine went through. In a way Ben has fallen further, his actual soul is blackened and breaking but Kaine just sees those pretty boy looks and it burns him up.
Theyll be friends in the end. But then, they actually always have been. Apart from Kaine trrying to kill Ben regularly. Well they are more than friends I guess, brothers.
I want to see Janine back and a follow up to Redemption Part 2.
Ben has a point about Kaine too. The way Kaine treated Janine and Ben and killed people, not a hero. But then he was in terrible pain. Its about empathy. Ben until recently always had empathy, it was made him such a great guy, better than Peter even imho. The best Spider-Man so far. But when he lost that, when the Jackal took that he fell, far and fast.
THAT for Ben is pretty scary stuff. And Kaine is like... 'But you were meant to be better than that! You had all the breaks! You can't just be like me!!!