I thought Perry got out because of a DEEP divide (they've never spoken since) he had with the other members. I seem to recall he had to take a break for health reasons, and the rest of the band said "come back or we're going on without you." So he left.... very bitter.
It was a combination of things. The first time he left (in the middle of the Raised On Radio tour in what, 86, he was burned-out, his voice was feeling "toasty" and after personal demons, his mom passing and life going quickly by when they were doing a massive amount of shows year after year, he left the band.
There as rumor that Steve had lost his voice at the time. UNTRUE. I say that for two reasons, first, I have a good friend whose band was hired to play Steve's Birthday Party at his Hanford home one year, and during their set, Steve jumped up on stage and did a Sam Cooke song with them, and tore it up. "Whatever the rumors are, I heard it firsthand, Steve still has his voice" is what my friend said. Then, a few years later when Perry did his Solo album For The Love Of Strange Medicine, we saw his concert at the Warnor's Theater in Fresno, and though he wasn't say, in Infiniti Album form at this Zenith, he still tore it up- Faithfully, etc he pulled off well, but I understand that tour was a mixed bag for him- neurotic in a way and I mean no disrespect. ie: "Is my voice going to work tonight, or it is going to SUCK?" every single night before the show.
Again, you don't run a thoroughbred into the ground, and Herbie Herbert all but did that. Guitarists can heal their fingers, drummers their hands, but you don't screw with vocal cords. It's true. As both a guitarist AND a singer, I can vouch for that 100%.
The hip issue is when he left the band a second time after their reunification album Trial By Fire in the 90's, and they didn't go out to tour because of Steve's hip. They finally tired of waiting, and I can see both sides, "hey- we need to tour for album support", and "hey I'm in pain and I'll decide when I go under the knife"...he told them after they revealed they had been "checking-out other singers" which threw him for a loop and, told them 'well go ahead but don't call it Journey'. "Don't crack the stone". They decided otherwise and Steve called up his attorneys "to get the divorce papers filed"....geeze such ugly, personality stuff. I'm not taking sides. I can see both their views. And Perry inasmuch admitted they weren't getting along anymore and couldn't stand to be around each other for very long. I beleive he took personal responsibility for his own bad behavior- he also has not mended fences, nor does he intend to from what I gather, with Jonathan Cain. I have my suspicions as to WHY but don't know it to be fact, so I'll shut up about it.