For better or worse, that's just kinda...how it goes in both the Batfamily and fiction in general. There's more to suggest they're all pretty much cool with Jason now than there is to suggest that they hold any serious grudges. Regardless of if they should.
Especially Dick, who's straight up called Red Hood one of his brothers and thinks about him pretty fondly, along with his the rest of his family, as recently as the first issue of Taylor's book.
Whether or not it makes a lot of real world sense, that's just what happens when someone who used to be the bad guy joins the main cast. Just look at how many characters here used to be villains:
Six, if you didn't know. And two of them have been responsible for straight up planetary genocides (Four if you count the future versions of the Androids). Hell, one of them is (kinda) responsible for the death of the main character's best friend and now he's the guy that that same character trusts his son and granddaughter with.
Or, using your avatar as an example, Bakugo. He may have never been an antagonist like Jason was but when you look at the way he treated Deku for most of their lives, it's also kinda hard to believe that the two of them would be as close as they are now. What he put that boy through for years could have been seen as emotional/psychological abuse.
So it may not be totally realistic but I don't really have
that big a problem with Jason's face-turn and the fact that he's mostly cool with the family now. In fact, I kinda prefer it that way. I always hated Pre-Flashpoint Red Hood. Plenty of characters, both in and outside of comics, have done way worse than him and still got to be redeemed. So Jason's not the hill I'm going to die on when it comes to a character not deserving redemption (that honor belongs to bitch ass Professor Snape and, funny enough, the live action Red Hood in the Titans show)