I find this an interesting question, particularly because I believe that people learn more and gain stronger skills when they work with a chavrusa (study partner), as opposed to attending a shiur. I came up with several reasons for attending a class, including:
- It's a communal experience, bonding with friends;
- It's a way to publicly demonstrate religious commitment;
- It's a way to support the existence of such classes, which benefit the community as a whole;
- It's an opportunity to be in a safe Jewish environment, with people who share your background and ideas.