Many news sources are already pointing out the obvious problems Simmons is going to have proving any sort of ownership over the rock horns. For starters, John Lennon shows off the symbol on the 1966 cover of “Yellow Submarine/Eleanor Rigby.” Standardized American Sign Language arose over a century and a half before that in 1817.
Essentially, trademark exists to protect buyers from getting brands confused. In order to trademark something, “an examiner would consider the likelihood of confusion and, possibly, whether it’s too generic to be associated with Simmons,” the Hollywood Reporter said.
It’s not totally unheard of to be able to trademark a gesture like this. But in this instance, it seems like the sign is pretty universal and not very strongly associated with Gene Simmons and KISS alone.