I agree they are useless for forward driving, but could come in handy when backing into places and making sure you don't run over the electric service, water spout, sapling, boulder, kids bike, etc...as sfergie631 said.
2015 Jayco Greyhawk 31FS-"Scamper"
2015 Subaru Forester 2.5i Prem. 6 Spd
Blue Ox Aventa LX Tow Bar
2014 Jayco Jay Feather X23B-"Glampy"(Sold)
DW, DS, DDx2, and Bandit & Fletcher