I'd say there are a couple of things that would attract consumers: LCD displays are generally brighter than plasmas, so they'll look more immediately impressive. Secondly, they don't fade over time and don't suffer burn-in. Not all consumer choices are based on quality of performance regardless of other factors. The brighter display will trump subtlety of shades, tones, and gradations to the average buyer. Throw in the longer life and immunity to burn-in and it's an easy sale.
Why are LCDs more popular than plasma?
I have a rough time seeing differences in picture quality between brands and models, but the difference between plasma and LCD are overt even to me. When I go to bestbuy, fry's, etc. and gaze at their displays of flatpannels, plasma televisions just look beautiful, despite the reflections, while LCDs just remind me of working on my laptop. Is there more merit to the quality of LCD than I observe or is there some other reason LCDs outnumber plasmas?