I almost always read in the news/press that dentists recommend to brush teeth two times a day for 2-3 minutes.

This drives me crazy, because it does not make sense; The point for dental health is to systematical clean every surface of your teeth twice a day (and use inter-dental brushes/floss once a day). For me, brushing my teeth takes around 6 minutes, if I hurry up. For someone faster it might be possible in 1 minute.

So, why do dentists always give the 2-3 minutes recommendation?