Back when he was the undisputed overlord of the entire Doctor Who universe, Russell T. Davies was often heard to say that he liked to reboot the series at the start of every season, treating each season opener like it was ‘Rose’ all over again (which explains the high turnover of companions). Barry Letts did a similar thing with ‘Terror of the Autons’, effectively rebooting the entire series to better suit his idea of how it should be.
“Listen to that! It's the sound of the planet screaming out its rage!”
For a science fiction series with such a long and diverse history as Doctor Who it is somewhat surprising that ‘Inferno’ is the only time in its original 26-year run that everyone’s favourite Time Lord ever ventured into a “parallel space-time continuum”. Can’t understand why they never did it again because ‘Inferno’ is very good indeed.