Ok, I am going to assume that there is something to this ... because I think it would be cool.
In 1317 Pope John XXII issued a decree against the alchemists De Crimine Falsi Titulus VI. I Joannis XXII. [circa annum 1317 Avenioni]:
"Alchemies are here prohibited and those who practise them or procure their being done are punished. They must forfeit to the public treasury for the benefit of the poor as much genuine gold and silver as they have manufactured of the false or adulterate metal. If they have not sufficient means for this, the penalty may be changed to another at the discretion of the judge, and they shall be considered criminals. If they are clerics, they shall be deprived of any benefices that they hold and be declared incapable of holding others."
It seems the Church's basic issue was on of counterfeiting and general fleecing of the uninformed. With Rokari the issue may be one of attempts to reach beyond their caste for alchemist, who would technically be craftmen, practice magic as though of the Wizard cast.