Baseball people didn't think it was a fleecing, from a pure baseball trade value stand point the Marlins did quite well. The outcry was because of how the Marlins handled FA signings the year before, their stadium issue, and Loria being a dishonest snake.
The Marlins traded Buerhle and Reyes who had contracts that exceeded market value (due to very low year 1 salaries), Josh Johnson who was a valuable asset, but only had 1 more year of control, and Bonafacio who was a pretty solid 2b/UTIL guy, and got multiple useful, young, controllable pieces. Buerhle and Reyes, in theory, should've had negative trade value at the time of the deal.