Going back to the title of this thread, is this one of Peter's infamous ruderies?
I too have fond memories of Peter, especially when he came to the White Lion Folk Club in Wherwell. He just did a stomping set, and didn't say or do anything untoward.
I can understand why people didn't like his voice, if indeed that was his natural singing voice. He played about with it in an extreme way, and created a unique sound. This can be uncomfortable listening if you are not ready for it. There are songs in the back catalogue that sound relatively "normal", but they are in the minority. If you acquire a taste for his sound, however, it can haunt you for the rest of your life. But like a lot of good things, you need to be in the mood for it!