In parts of the country where the weather is always hot and dry, yes, you'll see different building materials in use. Exterior materials like brick, concrete, stucco, adobe, and the like, are used because they are cooler and don't expand and contract in the heat of the day and in the cold of the night, which is what vinyl would do. This excessive 'abuse' of the vinyl would age it very quickly. It's not that the vinly can't take it - It's that its life would be shortened. Los Angeles, as with 'locations' like Phoenix and Dallas and so on, have the right 'ingredients' locally to make building materials like brick, concrete, etc., etc.. Heck, the Anasasi (sp) Indians can't be wrong. They used mud and straw to build their homes. They were durable and cool. So, in a sense, if you want to 'fit in' with the location, then use the material(s) that work best. Oh, it's quite possible you won't see brick in earthquake-prone areas. There are other factors that come into play (other than those I mentioned) as to why certain materials are used, or not used.
I'm sure that preference is a big factor too as to why vinyl isn't used. I'm sure most folks out there would like to use it but it just won't fit in. Oh, as you know, vinyl designs 'mimic' painted wood strips (or planks.) Well, LA, Phoenix, Dallas, and the like, are very, VERY short on wood, so having that 'look' on your house wouldn't fit in. Besides, wood was probably most used for structural purposes and for cooking and heating than was used for 'a nice look'. (It would probably seem like a 'waste' of good wood if you were to side your house w/it!)
Others may have more to offer. My best to ya and hope this helps.