The poet and author and one of the memorial's consultants, Maya Angelou, told The Washington Post, yesterday, the quote makes King seem arrogant. Actually, she put it in harsher terms.
"The quote makes Dr. Martin Luther King look like an arrogant twit," she said. — kcrw.com
Today, All Things Considered's Melissa Block spoke to memorial's executive architect, Ed Jackson Jr., who explained the quote was paraphrased because of design constraints. At first, he said, the quote was going to be placed on the south face of the monument, but instead the designers decided that they wanted visitors to see the quotation ("Out of a mountain of despair, a stone of hope...") that explained the whole concept first. So they decided to move the quotation to the north side, where the sculptor had already done some work adding striations that left little room for a lengthy engraving.
That's the technical explanation. But Jackson also said he disagreed with Angelou. He said the quote did not make King sound arrogant and said the memorial includes 14 other quotations and that the full experience cannot be determined by one small part of it.