Dinah's pissed at Oliver because he's pretty much tossed out most of his life. He's nearly lost everyone that he loves and it's taken forever to get them back. As of late, he's come around to be a fully on family man. He had Connor when he was younger despite the fact that he says he only met him 20 years after the fact. Connor was raised in a Asharam, where he learned similar skills to his father. The two came together and he's been watching over his son ever since.
As for Roy Harper, he was the first child raised by Oliver, turned into Speedy then Arsenal and now Red Arrow. Harper felt neglected at one point and experimented with drugs, nearly costing his life. Ollie and the others saved him and he went on to evolve into the other incarnations mentioned in the prior sentence. He's currently part of the Justice League.
Dinah and Ollie have a more complex relationship. It's a lot of love, but Ollie's at fault for screwing up a lot of things. Usually when it comes down to things it's always about his ego or at least was, but since he's been focusing on his city and his family things have changed. He's a family man these days. Going as far as giving up his spot on the Justice League for Roy.