I think people become more intolerant as they age; in school you are forced to interact with people and learn new things. But as you age you're free to ensconce yourself in your ignorance and shut out or block dissenting voices and opinions.
Some might counter that there is always work to expose one to new and different ideas.
Yet, at work one generally engages with people on a more impersonal, professional level.
And in work the sort of ideas you engage with are generally potentially less scary or discomforting, especially ideologically.
Work is also more instrumental than school; you're typically trying to earn money and/or make a living, rather than think about deep issues.
People are also more guarded and less themselves at work; everyone self-censors.