One of the most kosher Shabbat meals I ever ate was at the home of my cousin whose family has not been observant in many generations. My cousin Claire and her husband live on an island off of an island off of Vancouver - it takes a mini-plane and a ferry to get there. We met over a genealogy website, and she invited me to come visit one summer when I was in college.
Although she has no connection to kashrut or Shabbat, she asked me extensive questions and made it a top priority to make sure everything was done right. She bought me an entire set of dishes and cooking items, and bought anything in their tiny general store that had a hechsher. We made a Shabbat meal, and sat up watching the candles and talking. Again, although she has no personal interest in observance, she made many positive comments and nothing negative, and this is her general approach to life as well. (For example, instead of using terms like "ultra-orthodox," she says "enthusiastic" which I feel conveys a really positive attitude.)
Now, let me tell you about one of the most traif Shabbat meal I attended. It was at the home of a rabbi who would later steal $3000 from my husband. This person was considered fairly high up in his yeshiva, and was the rav of the local shul. He spent the entire meal criticizing and ranting about all sorts of Jewish people, with a real hatred in his voice. He had complaints about women, including ranting at his teenage daughter about wanting to go to Israel after high school. He and his family did nothing the whole meal to make me feel welcome in their home, since I had never met them before, but instead just ignored me.