The knowledge of a Satguru like you is correct. Should we not condemn the false-knowledge preached by all these fraud preachers?
In this world only atheist is the fraud preacher and you should condemn such fraud preachers who preach that God does not exist. All the other preachers who accept the existence of God are not fraud teachers and therefore nobody should condemn them. A person who teaches that you should not go to the school at all is a fraud teacher and should be vehemently condemned. But all the teachers in the school or college or university are not fraud teachers. They are true teachers who suit to different levels of the students. You should not scold the schoolteacher after going to college. When you leave the college and go to the university you should not scold the lecturer of the college after hearing to the University professor. The schoolteacher, the college lecturer and the University professor constitute the ladder of knowledge for all the students to climb up. The lower step should not be condemned after reaching the higher step. In the lower stage of knowledge there will be some errors and mistakes, which suit the students of that level. Gita says the same (Sarvarambhahi doshena).
The schoolteacher preaches the idol-worship, which is suitable to the lowest cadre. In this stage people are with full jealousy and egoism. Their mental capacity is also low. Due to egoism and jealousy they cannot worship the human form of Lord.