I honestly think that the long shows absolutely played a part in the overall damage to his voice. The fact that he was still nailing notes at the 3 hour plus mark says that he was not holding back and giving his all for that whole time. That is going to wear your voice out way earlier than if you were playing two hours and under each night. Sure, it gave people incredible long shows, but in the end I think the smart thing to do would have been to cap shows at the two hour mark. These songs are tough to sing and will wreck your voice, especially when you have 3 nights in a row, which they did often. Obviously Jon was getting very little advice on his voice back then, if he was he would have been advised to do no more than 2 shows in a row and no more than 2 hours a night.