The hacker is always the last to leave, late at night, which impresses the MD
Counterpoint:
Hacker uses disciplined development languages and RAD, dynamic languages (e.g., Perl) to get their work done during regular 9-5 hours (often ahead of schedule), and never needs to work late or demand more budget/schedule/employees.
Slacker throws sh*t at the wall until something sticks, relies on the buzzword languages de jure (Java, .NET, etc.), ends up putting major extra hours in to cover their own screwups, goes over schedule and over budget.
Slacker gets awards, promotions, and raises, while hacker gets layed off, since PHB sees "Slacker goes the extra mile to get difficult projects done", while "hacker doesn't seem committed to the team".