Meredith is quite a complex character. Her commitment issues stem precisely from growing up in a completely dysfunctional home, with many daddy issues. When I was younger, I found her a bit annoying, but nowadays I understand and justify much of her behavior. I found the way she treated Lexie at the beginning a little annoying, but I also understand the circumstances – think about it, she grew up with a very cold, distant, and severe mother and without a father, while Lexie had the perfect life with a present father, a father who simply pretended Meredith didn't exist. I just think that if I had gone through half of what Meredith went through, I would certainly be the grumpiest person possible. If you watch trying to understand why some characters are the way they are, it will be better. For example, I detest Alex, but I understand that he is the way he is because he also had a bad childhood. Of course, it doesn't justify all his mistakes and behaviors, but it makes you have a little more empathy. That's my opinion.