One of the great gurus that comes to mind is Kanch Paramacharya. His work - Deivathin Kural (VOICE OF GOD) is still available for people to read and follow. When such lofty teachings are available, why get upset over as few charltans with siddhis not living upto erxpectations?
http://www.scribd.com/doc/8594933/Deivathin-Kural