Well for one thing, cost. If a Lexus or Cadillac was as affordable as a Buick, it would not be considered a luxury vehicle. People with money buy cars like this BECAUSE of the statement it makes, because it stands out and lets others know that they have money and/or are important. They are "entry level" luxury brands because it's not exactly an A to B car like a Cavalier or a Nissan Sentra, it's a little more comfortable to drive, it costs a little bit more, but you don't have to make six figures to buy one. No one makes six figures a year and buys a Ford Focus....unless they are a tightwad or giving one to their 16 year old. It's just the way things are.