In addition to the 12 Bears games this year (including the pre-season and the playoffs), Soldier Field is home to concerts, special events, soccer matches, high school and sometimes football games.
The Chicago Public League Championship and the Prep Bowl (Catholic League vs. Chicago Public League) are both held at Soldier Field during the season. The next college game that will be played at Soldier Field will be in 2012 when Notre Dame will plays Miami. That's a total of 15 games, almost every week of the season.
Installing FieldTurf makes more financial sense because the city will pick up most of the tab. This will help grow the bottom line for both the Bears and the Chicago Park District. Besides, the city can hold any kind of event they want without having the Bears and the NFL worrying about the conditions of the field.
Playing on grass won't break the Bears tradition. It doesn't make the Bears any less soft or less physical of the team. The Ravens play on FieldTurf and they're not soft. How about the Patriots or Jets? The Packers or Vikings? How about the Colts or the Saints?
Most city parks and Chicago Public High School fields are in better condition than Soldier Field. I'm all about grass but for what the city wants to use Soldier Field and for what the Bears and the NFL want, its not the best option.