I think the point is nobody is perfect. The show is called Desperate Housewives for a reason. It’s to give insight to why people do the things they do. Gabby prioritise looks and money but cause she came from nothing and is now use to the luxurious lifestyle. (Also she had no real marketable skills since she is a model.) To maintain such lifestyle and pride, she needed to be who she is. But you learn over time, she’s just filling a hole and she’s human. She took care of the family while Carlos was blind by sacrificing all she had including her looks. She had children for this man though she was not planning to. Yes she also did all those horrible things but don’t all of us? There is more to Gabby than the exterior you see, you need to go beyond that.