Why have the LDS Prophets made the following statements regarding the beliefs and teachings on traditional Christians?
"What is it that inspires professors of Christianity generally with a hope of salvation? It is that smooth, sophisticated influence of the devil, by which he deceives the whole world."
- Prophet Joseph Smith, Jr., Teachings of the Prophet Joseph Smith, p. 270
"...all the priests who adhere to the sectarian religions of the day with all their followers, without one exception, receive their portion with the devil and his angels."
- Prophet Joseph Smith, Jr., The Elders Journal, v. 1, no. 4, p. 60
“Nothing less than a complete apostasy from the Christian religion would warrant the establishment of the Church of Jesus Christ of Latter-day Saints.”
- Prophet Joseph Smith, Jr., History of the Church, v. 1, p. xl
"Brother Taylor has just said that the religions of the day were hatched in hell. The eggs were laid in hell, hatched on its borders, and then kicked on to the earth."
- Prophet Brigham Young, Journal of Discourses, v. 6, p. 176
"When the light came to me I saw that all the so-called Christian world was groveling in darkness."
- Prophet Brigham Young, Journal of Discourses, v. 5, p. 73
"With a regard to true theology, a more ignorant people never lived than the present so-called Christian world."
- Prophet Brigham Young, Journal of Discourses, v. 8, p. 199
"The Christian world, so-called, are heathens as to the knowledge of the salvation of God"
- Prophet Brigham Young, Journal of Discourses, v. 8, p. 171
"Christianity...is a perfect pack of nonsense...the devil could not invent a better engine to spread his work than the Christianity of the nineteenth century."
- Prophet John Taylor, Journal of Discourses, v. 6, p. 167
"Where shall we look for the true order or authority of God? It cannot be found in any nation of Christendom."
- Prophet John Taylor, Journal of Discourses, v. 10, p. 127
"What! Are Christians ignorant? Yes, as ignorant of the things of God as the brute beast."
- Prophet John Taylor, Journal of Discourses, v. 13, p. 225
"What does the Christian world know about God? Nothing... Why so far as the things of God are concerned, they are the veriest fools; they know neither God nor the things of God."
- Prophet John Taylor, Journal of Discourses, v. 13, p. 225
"Believers in the doctrines of modern Christendom will reap damnation to their souls."
- Apostle Bruce R. McConkie, Mormon Doctrine, see pp. 45-46
Each of these statements expresses that Christians of their day were utterly deceived, ignorant, and unsaved. Why did they have such negative views of traditional Christian teachings?