I couldn't possibly disagree with you more about the Colon deal. A few things...
It wasn't just Fossum that was the sticking point. It was Sanchez, Fossum and Hillenbrand. And we got Kim for just one of those pieces, who could be more important than Colon.
Fossum is a very good pitcher, and for the first two months of the season was pitching better than Colon.
Colon's in his final year of his deal.
We can't keep giving away young prospects/players for one year rentals. See Jeff Bagwell.
Overall, Epstein and co. have realized that we cannot compete with the Yankees and just buy what we need all the time; while the Sox have a large payroll, it can't go to far above 100 mil in Fenway. Thus, we need to make better efforts to groom our talent. That means not sending away our best talent because "this is the year..."