I think it was a combination of both his not wanting to be on the show (he said OLTL's writing was "even worse than Another World's," YIKES!) and TPTB's realization that he was more trouble than he was worth.
Erika Slezak said that on his last day at the studio, Reinholt ranted and raved his way down the hallways and out the door. She also said he was "crazy" while on the show. but calmed down in later years. When cutting into the soap's anniversary cake that year, the producer at the time "joked" that the cake should have been GR's heart.
It looked like there was no love lost on either side.
Unfortunately, however, the character of Tony (who should have been a major and influential part of the show) failed badly after Reinholt left. It was a relief when they finally killed him off after three failed recasts.