Do you know anything about the family cultures of Cate's family of origin? In the family that I grew up in, offers of help were not made. It simply wasn't done unless maybe if it were a very large holiday dinner hosted by an elderly person--and then tweens and teens might be voluntold. On both my mother's and father's sides, family dinners were always hosted and family were guests unless they lived in the same household. If they had a separate household in the same dwelling, they were still guests. It could be seen as insulting to your host to assume that they needed help in hosting you. Also, bringing or offering to bring a dish was not done. This is how I grew up and for me, it will always be the "right" way.
Then I married a wonderful man from the mid-west with a family culture similar to the OP's post. Everyone automatically brings a dish to all family dinners (which are usually buffet style) and they always jump up to help host and clean. Luckily, my in-laws see this action as more of a gift rather than an obligation and I'm sure they don't mean it as an insult (even though my first thought is still "insulting"). For my DH, this will always be the "right" way because that's how he grew up.
My DH is uncomfortable in my family's culture because it is so different from his. I'm uncomfortable in his family's culture (but they are absolutely the best in-laws ever!). The hosting-but-not-really-hosting thing really throws me for a loop. Then add to that the fact that I don't cook. DH does all of our cooking. He loves being in the kitchen. I'm uncomfortable and awkward in my own kitchen so you can just imagine how I am in other people's kitchens. I am absolutely miserable and a bit lost. I don't know how they want things done or if I'm doing something wrong.
Whether it's me dealing with DH's family culture or him dealing with mine, it's hard to break away from how we were raised. We can intellectually understand our differences but our own ways will probably always be the "right" ways for each of us. I don't think that there is only one true "right" way that works for all families or all people.