I am not saying the sisters should worship Lincoln or be mary sues. Siblings do fight, but there needs to be a reason to have a fight. A lot of the times the sisters fight or just flat out ignore Lincoln for pretty much no reason. If those were younger siblings against Lincoln, then it is understandable, but the older ones? Get that shit out of there. Not to mention that Lincoln himself in the future seasons has been written off as a dumbass or a flat out pussy. Even tho, when the show started, Lincoln wasn't like this in the show. Luan is a pshycopath in April Fool's and in real life or if her parents weren't bafoons, then she would be thrown in a mental asylum. Oh yeah, ruining peoples social lives is funny. Lola pretty much acts like a devil at times, when she doesn't get her way or blackmails people and Lynn Jr. has SO MANY flaws, that I don't want to describe them.
Yes, not all siblings get along, but that doesn't mean they shouldn't try to do so. The show is about family. So why not have the sisters learns from their own mistakes and have them learn something in the process? Or when they do something shitty towards their brother, they should apologise and try to have some of the sisters talk things through with Lincoln as to why they are like this towards him. Is that really that hard? Yes, they can still have the characters to have fun, but the characters in the show should also learn from right and wrong and make it consistent or relevant in the next episode, so it can be seen that the characters can change for the better as most people do over time.