because we are out of the 80's (and we've learned you can't turn it to gold)
I'm amazed that people do this...I remember doing this with my model 2 for gawd's sake (yes, I'm old). Add a battery (ding ding), a recorder, a gyro, a rear-view mirror, a squirt gun, a fart machine, a dvd player to watch movies during boring shots, a sign-up sheet and pen for the cute extras, a business card dispenser, a printer to spit out invoices while you walk by the upm, a spare pair of shoes, deoderant, a back-up gimbal...something useful -- not dead weight!
rb