Well if they called themselves Islamic Death Cult the BBC would still call them the ‘so called’ Islamic Death Cult.
There would be no reason not to, if the group chose that name theres nothing factually incorrect in using. In the case of the BBC reporting of IS, where the group themselves are inconstant and unclear as to what they are called, various media and government agencies have had to use some name or other to describe them and ISIS and ISIL etc have been chosen at different times as they reflected the stated aims of the group at the time those names were coined. However, the group haven’t chosen that name and the BBC haven’t chosen that name. The BBC are reporting the name that other agencies are using and indicating that with the prefix ‘So called…’
If other agencies decided the called the group Islamic Death Cult, but thats still not consistently the name the group use to describe themselves then the BBC would refer to them as “So called ‘Islamic Death Cult’…” because thats what the phrase ‘so called’ means.
, it’s utterly pointless rhetoric.
Its not rhetoric, its english.