The BBC was banned from broadcasting the voices of Sinn Féin MPs who had been elected to the UK parliament.

So starting from the vantage of a news service banning interviews with members of its own country's parliament, outlets like Russia Today have to be below that bar.

A number of Russian outlets are listed as unreliable - perhaps some of them are tabloids like English language tabloids, but it seems that all Russian outlets with a standard mild or heavy support of their government are not OK, whereas this is not the case for the US and UK outlets with the same mild to heavy view of things from their country's vantage. It is just the myopic view of the English speaking countries.