It's all in how you word it, bro. The whole "mainstream car audio is junk" mentality is played the fuck out. It's far from junk. Yes, the prices are outrageous, but that's the nature of the beast. Are Nike basketball shoes REALLY that much better than Converse? No, they're not. Both companies, in short, use similar materials to build a similar product. The real difference is in the marketing and such.
Companies like JL Audio market themselves to a larger group of people, which leads to increased demand, a broader range of recognition and higher prices.