Coming from someone who soaks his brush for 15 to 20 minutes this remark is actually rather funny. Saturating the actual hairs of a brush takes five minutes max. What little extra moisture manages to creep into the depths of the knot due to capillary action during the rest of the soaking is easily balanced by using a little more water during the shave.
The brush only soaks that long because it takes me 15-20 minutes to take the dog outside, pick out my wardrobe, and shower before I shave. I would only keep it in there for 5 minutes if I didn't have this routine. The excess soak time is not deliberate. I do it first thing because sometimes, in my morning haze, I forget to soak the brush. So I've made it the first thing I do in my morning routine.