"Church" is a Trademark
Though I am a protestant both by tradition and by free choice (baptized evangelical-reformed), I can fully understand why the Roman Catholic Church is firm in the defense of it's status as "church". This is a question of trademark protection.
The most dangerous challenge that the Roman Catholic Church faces these days does not come from individualistic Lutherans, Calvinists or Zwinglians, but from Scientology with it's perfect financial management.
In a very clever move, the Vatican has enlarged it's trademark protection to the orthodox churches in Russia, Byelorus, Serbia, Bulgaria, Greece, Turkey and the Middle East.
This partial exception to the Roman monopoly is aimed at easing the renewed tensions between Eastern and Western Christianism that had been fuelled by the activities by Roman Catholicm missionaries in Russia after the fall of the Soviet System.
No wonder if Chinese who want to be baptized tend to turn to become Lutherans rather than Roman Catholics - they will be safe from institutional constraints and will face less problems of trademark protection.