Jon has a vocal coach but part of the problem is that he probably needs a different one using different methods and Jon tends to be loyal to the people he surrounds himself with. Something is obviously wrong; something is obviously not working in terms of vocal coaching.
Jon never wanted to be a nostalgia band and thinks that by releasing new music, it means the band is still current. However, most of his fans attend his concerts out of the loyalty the band earned many years ago. These fans attend his concerts out of nostalgia for the band and nostalgia for youthful days. The current reality comes as a harsh awakening--the contrast between now and then is too much and becomes sad/annoying. It is not the band that is the problem but Jon. The exception is, of course, are those few nights when magic happens and Jon becomes the frontman they yearn for.