Let me propose an analogy of what you're saying: some say a roof is important on a house, but without the basement, a house would collapse. Without the roof, on the other hand, the house would be fine for quite some time, especially in a warm summer climate, like LA.

In reality, a roof and a basement on a house are like marketing and engineering: both are necessary and neither is sufficient for a good product. Engineering without marketing is blind, and marketing without engineering is lame.