Because ever though Perk and McGee are both frequent members of the ASaF (All-Shaqtin-a-Fool) First Team, McGee at least has Age and physical talent on his side, leaving some minor hope that he may ONE DAY become a basketball asset to a team.
He might be the basketball equivalent of an absolute moron, but there is no question that the guy is an impressive physical specimen who is a pretty capable rebounder, shot blocker and even scorer (shock).
Over his career McGee has averaged (Per-36 minutes) 15 points, 54.1% FG, 10 rebounds, 0.8 steals, 3.3 blocks and a surprisingly reasonable 2 turnovers.
Perkins (Per-36) has averaged 9 points, 53.6% FG, 9.5 rebounds, 0.5 steals, 2 blocks and 2.5 turnovers. Clearly McGee has been the more productive player over his career.
In fact surprisingly, as bonehead as he is, McGee has been pretty impressive in the minutes he's played. He's career lows Per-36 have been 13.1 points (2010-2011), 7.7 rebounds (2013-2014), 2.4 blocks (2008-2009) and 44.7% FG (2013-14)...so even if you took the absolute worst stats he's ever put up and combined them all into a single big bad season, he'd still be a pretty decent starting center.