I've dealt with this a lot for most of the last decade, as I grew up in Florida and currently live in the Midwest, and often meet people from both the east and west coast. I imagine they think of family vacations to the world-famous beaches, Disney, resorts, and restaurants, they think of the "sunshine state" motto, and all that. I've met people who've encountered similar reactions being from southern California, Seattle, New York, Paris - etc.
I have found the key is to find a polite, positive, upbeat script that works for you. Mine generally goes like this:
- Politely acknowledge positive aspects of where you are coming from. Great lines include: it is a great place for family vacations, I got to meet and learn about a lot of different types of people, the food is great, its glamorous or exciting (or laid-back and relaxed), note the nicest season they have, some sport, etc. Pick something that people often think of, and that you don't really disagree with.
- Pick a simple, honest reason that you moved. For instance: to be with family (you don't have to specify exact relationships if this makes you uncomfortable), the cost of living, employment prospects, etc. In your case, just "I wanted to be closer to extended family, and I have a lot of relatives here".
- Finally, my favorite part - offer a positive, honest thing that you like about this new place, and bonus points if it's somewhat insightful. Best results are when you point out something that makes them realize they know they should be more thankful for, but take for granted. This is personal and varies by place. Examples: the common friendliness of strangers, local food and/or cultural events, being close to the sea, outdoor adventures, architecture, whatever. It's good to practice this with locals in restaurants, bars, social events, etc, so you can see how people react and find the right fit. This naturally leads into questions like "what do you do for fun outside of work", or even answers them preemptively.
The real secret is you have to be genuinely sincere to get the best results, and you have to suck it up and get over your personal negative feelings about places you've been or you are going to come off as unpleasant, immature, negative, unreliable, flaky, unstable, or worse. These are all perfectly reasonable traits for people to want to identify and avoid, so in the case that any apply to you consider this a necessary growing experience.
If you really, really hated a place, I have at times found it possible to find socially acceptable complaints, but this can be touchy. I've succeeded with things like heat/cold tolerance (moving from the desert/tundra), violent crime/human trafficking when moving from areas where this is big, and crowded/deserted (from big place to little, or little place to big). But I've found that such negativity far too commonly taints the conversation, so I suggest you "keep to the sunny side" and compare positive traits.
Finally, as a last piece of advice - there's a good chance that you are bringing a 'vibe' of desperate, impatient, annoyed, or anger to your job interviews, and in my personal experience this repels good opportunities and attracts only job offers at dysfunctional places (I've been there, and at the time I couldn't figure out what I was doing wrong). When you are going through harsh times and big changes I know it can be hard, but it's important to get yourself into a good mindset before you do an interview - exercise, watch some funny clips, affirmations in the mirror, stare at cute pictures of cats, whatever works for you. It doesn't always come easily, but I've found that just temporarily psyching yourself up into a good place can make all the difference in the world. Happy people like being around happy people - and the spiral works in both directions.