This article by Minyanville.com is interesting and amusing about stupid business decisions. A couple could have radically changed technology as we now know it. The Google founders did not want their company to interfere with their studies and in 1999 had tried to sell outright ownership of their search engine Google to Excite and a number of others which are now bankrupt while Google is worth $180 Billion and their shares of the company worth Billions each.
Also T. Boone Pickens had sought to buy Microsoft in 1979 but after offering in the relatively low millions (conflicting stories of how many) it was turned down and it was announced the company had around $40 Billion in cash alone as of a year or two ago.
While other examples included an agent telling the musical group one of the most successful of all time they would never make it in show business and the guy who created the oil drill having failed to patent the idea and having died a poor man as a result among other foolish business decisions.
See Justin Rohrlich April 23 Minyanville Stupid Business Decisions : Excite Rejects Googles Asking Price.