The criteria I use is that any religion that was revealed by God through a Messenger is a real religion.
So I would consider Hinduism and Judaism real religions. the problem with Hinduism is that it is so ancient that we cannot trace it back to an original founder, and for me it is not worth the effort to try. Judaism is another matter because we have the Torah and the Bible, so if we believe those scriptures (and what Baha'u'llah wrote about Moses and the other Prophets) we have something to go on.
The way I see it is that there are many superstitious mythical beliefs that probably have nothing to do with God, so they are man-made; but there are also superstitious mythical beliefs associated with the true religions of God and that all goes back to what Baha'u'llah wrote about those religions having been corrupted by man.
“This is the Day when the loved ones of God should keep their eyes directed towards His Manifestation, and fasten them upon whatsoever that Manifestation may be pleased to reveal. Certain traditions of bygone ages rest on no foundations whatever, while the notions entertained by past generations, and which they have recorded in their books, have, for the most part, been influenced by the desires of a corrupt inclination. Thou dost witness how most of the commentaries and interpretations of the words of God, now current amongst men, are devoid of truth.” Gleanings From the Writings of Bahá’u’lláh, pp. 171-172
Speaking of superstitions, recently I found this quote from Abdu'l-Baha where he explains how the superstitions of older religions obscures reality and as he said, to such an extent has these superstitions have prevailed they have taken away the heavenly light of divine truth .
“Alas! that humanity is completely submerged in imitations and unrealities notwithstanding the truth of divine religion has ever remained the same. Superstitions have obscured the fundamental reality, the world is darkened and the light of religion is not apparent. This darkness is conducive to differences and dissensions; rites and dogmas are many and various; therefore discord has arisen among the religious systems whereas religion is for the unification of mankind. True religion is the source of love and agreement amongst men, the cause of the development of praiseworthy qualities; but the people are holding to the counterfeit and imitation, negligent of the reality which unifies; so they are bereft and deprived of the radiance of religion. They follow superstitions inherited from their fathers and ancestors. To such an extent has this prevailed that they have taken away the heavenly light of divine truth and sit in the darkness of imitations and imaginations. That which was meant to be conducive to life has become the cause of death; that which should have been an evidence of knowledge is now a proof of ignorance; that which was a factor in the sublimity of human nature has proved to be its degradation. Therefore the realm of the religionist has gradually narrowed and darkened and the sphere of the materialist has widened and advanced; for the religionist has held to imitation and counterfeit, neglecting and discarding holiness and the sacred reality of religion. When the sun sets it is the time for bats to fly. They come forth because they are creatures of the night. When the lights of religion become darkened the materialists appear. They are the bats of night. The decline of religion is their time of activity; they seek the shadows when the world is darkened and clouds have spread over it.” (‘Abdu’l-Bahá, Foundations of World Unity, p. 71)