One is a 9, constantly scores, and actually runs inside the box. The other has no defined position, doesn't like to stay in the box for chances, and took half a season to start scoring. Considering the team's current deficiencies (the lack of a solid striker), the team's strengths (we know how to create chances with or without Messi), Messi's wages, and Messi's difficulties with finishing...then yes keeping Suarez and letting Messi go would have been the better option.
Hindsight's 20/20 though.
Hindsight's 20/20 though.