They were actually scamming to intentionally restrain supply, which is going to artificially increase market price. You get a giant group of the biggest suppliers together, have them all cut supply, and prices go up due to lower supply. According to the article, they were actually dumping supply below cost in foreign markets, all in an effort to increase price here.
You don't think that has an effect? "According to U.S. Commerce Department data, the wholesale price of eggs roughly tripled from 2007 to 2008. "
Sure, presuming you had perfect information and knew exactly what was going on, you could probably undercut that if you wanted to build the largest egg production business in the country to outmatch the rest of the businesses together. But the ultimate result of this would only be to return the market to normal, which would probably happen before you ever got your business off the ground, costing you enormous startup costs and netting you zero benefit.