He was known to be very outspoken, a rider who had a bit of a temper on the track, and his nicknames were "The Machine" and "The Businessman", for his very serious, focused attitude toward racing even as a 14-year-old amateur, and also his willingness to speak his mind including being critical of sanctioning bodies and their policies and rules. "The Businessman" moniker in particular was coined by Bob Osborn, owner and editor of "Bicycle Motocross Action" magazine. Greg personally boycotted the ABA for almost a full season in 1980 beginning with the Winternationals and ending with the Vans 5000 Pro Spectacular. He later led an informal pro boycott with numerous respected top pros against the ABA in 1983 over the method of how the ABA national number one was decided. Hill was also involved in a number of business ventures, such as motivational and how to books and video tapes; running a short lived BMX bicycle company, Greg Hill Products (GHP) during the 1980s which he later revived in the early 1990s and is still going strong, and teaching seminars instructing children on how to race. These are but a few examples of the drive to promote himself and BMX in the public eye.