The Propaganda Movement was anti-friar because its member felt that the friars in the Philippines exercised too much power. They felt that the power of the monastic orders was used for the benefit of those orders and not for the benefit of the people.
In the Philippines at that time, the monastic orders controlled most of the local parishes. This put them in a position of being in direct control of the people. The leaders of the Propaganda Movement felt that this power was being used to keep the people down. The friars were the ones, they felt, who decided which laws should be enforced and how. The friars, therefore, had more power than the people and more power than the legal government.
The Propaganda Movement was a liberal, reformist movement. Therefore, its members tended to distrust the Church and wanted to reduce its power. This is why the movement was anti-friar.