Psychology observation. Nick appears to be blaming Bob for how he turned out in the posted Tweet, but all signs point to Nick's narcissistic mother Celeste as the one who created the monster that is Nick today. If Nick has NPD, and I believe he probably does then this is a form of projecting blame on the weaker parent.
As far as I know Nick has never said a peep derogatory about his mother. Narcissists often idealize their narcissistic mothers so they can maintain the illusion of the perfect family unit no matter how fucked up their childhood was. Nick was clearly coddled and spoiled rotten by Celeste. And this could explain Nick's sister becoming a lesbian and moving far away from the family as the "scapegoat" In other words Nick was probaby the "golden child" aka a "mama's boy" Nick never separated from mommy and became an individual like normal mentally healthy children do, so every relationship he has is about finally discarding his "mother" It's not a complicated dynamic if you really study and think about it. Kayla is Nick's mother, and he tried to turn April into his mother so he could discard her in his mind too. Think Norman Bates relationship with his dead mother in Psycho.