While this is an answer that may apply to some folks who want to use heraldry, I think that for most people, it’s a little too simplistic. That is, I think many people’s interest in heraldry is far more complex, and interesting, than just a desire to set themselves apart from the riff-raff.
A couple of quotes that I’ve run across help to demonstrate this, I think:
"Why do people in the twentieth century still want an outmoded means of personal identification? The answer is, I believe, ... people are still looking for ways of laying down a solid foundation for their family. Heraldry is traditional; it is also fun, colourful, historic and respected." (Peter Spurrier, The Heraldic Art Source Book)
"I was mildly familiar with heraldry (I don’t think I even knew what the name was when I first started actively attempting to understand it...) and it dawned on me one day that these ‘family crests’ are powerful familial emblems that I could appropriate in establishing my own family traditions. ... I’ve found that friends are very interested in my coat of arms. I usually don’t say anything about it but when they see my framed COA [coat of arms] in my house or see my desktop background at work they start asking a lot of questions. After I explain that I’m not royalty, I haven’t been knighted and so on, many of them say, ‘That’s exactly what I want to do. It’s called heraldry? I’m going to check into that.’" (Sanjay Merchant, American Heraldry Society Forum, January 7, 2005)