Snaqwells wroteAs BktBallRef says; that's the only reason you need.
However, it's slower and not good on your legs.
It's also nice to see what's coming up. Can't do that with your back turned.
It would be a killer on my legs. When I watch JV officials do it, it makes my Achilles hurt just watching.
Full disclosure: I did this once working a middle school game sometime about 1990. Backed into a player and almost broke my arm.