Las Vegas has a low average household income. Also flights from there tend to be inexpensive. Travelers in Oregon will prefer to fly out of SFO as it is closer. If they actually fly out of Las Vegas, the profit margin for them will be much less as fares are higher on flights out of the San Francisco Bay area. Plus it lowers the load factor on flights from SFO. Also there aren't that many "Christian tourists" in Nevada. If you want that, fly out of Salt Lake. Many religious Americans actually have scruples, unlike Israelis, and will actually prefer to avoid going through Nevada (and especially Las Vegas).