No, you've got it wrong. I don't think Maya is selfish, so we don't agree on this. What i actually thought was, that it's funny you'd make a complaint out of Maya's supposed selfishness while at the same time you seem to worship a person who is selfishness incarnate.
"Quinn was taught a really dumb lesson by her father when she was little" might've been an excuse when she was a few years old. Maybe even when she was a teen. It no longer is one when she's an adult and can see for herself how wrong that lesson was, simply by observing people around her who support one another, can trust them, and are far better off this way.
It's not 100% understandable she's being selfish. At this point it's just an excuse, another one of many she's hiding behind to justify her choice to keep acting the way she acts. In fact, you could say that by the end of episode 9 she might be actually growing a little to admit as much, and maybe alter her behavior.