The 2010 Seattle Mariners have had 18 different players come up to the plate at least 100 times. 15 of those players have posted an OPS+ under 100.
This is the second-highest team total in baseball's modern era, matched by eight other teams - most recently the 2001 Atlanta Braves, who, thanks to Chipper Jones and the league's best ERA, still managed to win 88 games.
The highest total is 16, belonging to the 1980 Seattle Mariners, who wound up 59-103. The 2009 Seattle Mariners, meanwhile, finished with 14.
End.
edit, because this didn't sound bleak enough: of the three 2010 Mariners to post OPS+ figures over 100, one of them was a part-time player, and the other was a midseason acquisition. The one decent OPS+ belonging to a full-season regular is 112.