The Sinclairs are an unusual family - or are they?
The Sinclairs are defined by their strong characterisation as rich and arrogant people. They are seen as strange from an outer perspective, because they do their very best to hide any sort of emotions or feelings to the outside world. Never will they show signs of weakness or generousness.
The only reason the family is rich is Harris Sinclair, their Grandfather. Basically, everything that belongs to the family belongs to him. Especially mentioned, the island called Beachwood island. Every summer, the entire sinclair family will go to that island and occasionally bring some friends with them. Every core family has their own house on the island, which makes some sort of village on the island, featuring only one family. In some way, Harris also is the patriarch of the sinclair family. First of all, because of the reasons mentioned above, but that's not everything. He also controls every action and step of any Sinclair, and everyone has to follow. Not because of special reasons; he pays everything they need, and they need what he pays for them.
When Harris' wife, Tipper, dies, he becomes an entirely different person. He suddenly becomes depressive, and, most importantly, he reliefs a lot of the controlling pressure he exerted before. This obviously affects the whole family as well, and things start to change. This weird family dynamic is the main reason why I couldn't see myself as a member of the Sinclair family. I could never live with the everpresent knowledge that my dependencies on the money of my grandfather are so high that I basically lose my free will in exchange for living a life in some sort of luxury on our private island. Also, regarding said island: I hate to be sealed off from the outside world. I hate the quarantine like almost nothing else, and winter doesn't make things better. Why should I throw my Summer into the trash can as well?