In every aspect of life, you have large companies with efficiencies of scale coming up.
That's the trend during a market development, when the market matures and demand stabilizes, the large ones will get thinner and thinner margin and start to outsource, and eventually be overtaken by competitors. Just look at Compaq/Microsoft/Nokia/...
This is especially true for bitcoin mining, where the industry landscape changes so fast and no one knows for sure what will happen in the next 6 months. If some chip maker try to dominate the production, they will have the risk to bite all those useless ASICs when the exchange rate is lower than electricity cost. The exchange rate only depends on the market demand, it can go anywhere, the cost will be a baseline for valuation, but not a guarantee for the lowest possible exchange rate, since the cost will go down together with the exchange rate when difficulty is dropping
Due to such kind of risk, few business dare to make a long term plan and scale up dramatically, this is more like gambling, they have to reduce their risk by selling miners to individuals. If bitcoin exchange rate stayed at current level for another year, most of those businesses will go broke, and their useless ASICs will be picked up by hobby miners with free electricity