I've read many runig books about ultra runners (Scott jurek, dean karnes, Born to Run, etc). all these super-mega-ultra guys seem to have "loner" traits to their personalities but they have physical ability I could only ever dream of (I get injured when I up the miles, these guys seem to never be injured!). Having said i do enjoy reading their stories as they all reveal their inner battles we all have.
without wanting to sound too harsh, John Tarrant's myth is maybe bigger than his actual ability - against the top runners his illnesses generally stopped him short. If he ever got to run for GB in the Olympics it seems he wouldn't have finshed near the top. I also have to agree the comments above above the unbelievably selfish attitude to his own life to the detriment of his family, some things are more important than running...
at the end I can't believe how snooty the amatuer/professional debate was at the time, aren't we lucky today.