I very seldom have problems with dust, I’m just anal retentive and like to keep my expensive-ass equipment clean. I also tend to be an outdoor-type shooter so I deal with atmospheric contaminants more than most photographers.
One of the first real photographers I ever spent any time talking to was a guy named Everrett Brown. My then roommate and I watched him change lenses (both really nice L glass) on his 1D while his hands were covered with mud. When we asked him what his feelings were about sensor and lens dust he replied, “You kidding? I’ve seen guys change lenses in the middle of sandstorms in the Sahara. If you’re worrying about your equipment, you’re going to miss your shot. If you miss your shot, you’re not a photographer.”
/I’m paraphrasing there, but that’s the general idea.