" If anything's to blame for people here not being friendly, I would say that's it. They're not native."

Does that sound like someone who really welcomes diversity? For a big city, Houston is still having some growing pains as far as diversity goes.

To be fair, parts of the city can be rude and that's rude people from all nationalities including "native" Texans but that has a lot more to do with how crowded some parts of the city are getting. I lived in Houston proper for a long time but once I moved to the Clear Lake area things got much better. Some Texans may pride themselves on being friendlier than other parts of the country, but you know what they say about talk being cheap. I've been in Manhattan on a regular day and apart from it being much more crowded, I found just as many friendly and rude people. No big difference.