The QSopt parser assumes by default that a program's goal is to minimize the objective function.

This goal may be stated explicitly or overwritten in the OBJSENSE section, which contains exactly one data line. The data line's first and only field must contain one of the strings "MAXIMIZE, "MAX, "MINIMIZE, or "MIN.

Thus to state that the goal should be to maximize the objective add the following lines to your input.

        OBJSENSE
             MAXIMIZE

See also MPS format sections.