The latest issue of Doctor Who Magazine contains several features on John Nathan-Turner, producer of the show between 1979 and 1989. One interesting fact is that only three of the writers used in his tenure had written for Doctor Who before and, at least ten had never written for television before. Usually you would expect an established series to introduce new writers gradually, under the guidance of an experienced script-editor or team. Every other era of Doctor Who did this, except the first and the TV Movie in 1996.
Some people may argue that the inexperience of the writers shows and put extra pressure on the script-editors, who also came to the series without having written for it previously. Others see a freshness and diversity of ideas. In 1987 the BBC lost interest in Doctor Who, placing it in a graveyard slot with minimum support. In this time of turmoil, it would have been easy to fall back on experience. Instead only the first of the last fourteen stories was written by someone with prior Doctor Who experience. A poll in Doctor Who Magazine voted this the third worst story in the entire series.
The choice between new talent and experience is often difficult. Nathan-Turner deserves credit for encouraging different voices, many of whom have gone on to successful writing careers.