Over the course of two centuries, the image of a public figure undergoes striking transformations. Usually, the complexities that distinguished the person's life and career are bleached out in the process. The effective use of the person's image in political debate, in commercial activity, or in the manipulation of public sympathies depends on keeping the image relatively simple: easy to understand and to wield. Despite the generally well-intentioned efforts of academics to preserve an individual's complexity, the "real" person tends to get lost in a haze of nostalgia, opportunism, and ignorance.
In Hamilton's case, his fame never quite reached the critical mass of Washington's or Jefferson's, and during the periods when he was in ascendancy, his reputation stayed essentially one-dimensional: the clear-headed economic wizard with a suspciously positive attitude toward Britain. The complexities of his public career made it possible for opponents to paint him in stereotyped ways, while simultaneously hindering the public from forming an emotional bond with him.
For his own part, Hamilton never wrote an autobiography that would help to define himself for posterity. Nor did he manage to raise himself out of the messy trench warfare of early American politics and attain a more transcendent image of the glorious patriot. His accomplishments as revolutionary soldier and framer of the Consitution became imaginatively subsumed to the rather dreary, legalistic operations of finance that consumed so much of his time and embroiled him in such controversy.
Perhaps the fact that Hamilton was never President has limited the reach of his image in the American consciousness. If so, we should note the undying fame of others who never sat in the White House, including Benjamin Franklin and Thomas Edison.
The best explanation for Hamilton's demise as a figure of public adulation (regardless of his appearance in history books), has to do with his beliefs regarding his countryment. While Jefferson, Washington, Lincoln and others, whatever their ideological contradictions and personal flaws may have been, were perceived as "of the people," Hamilton was often regarded, with some justice, as an elitist who disdained ordinary folk and doubted their capacity for virtue.
He who believed that no man should be carried on the shoulders of a crowd, who suspected the crowd itself, would have seen the natural outcome of his philosophy: The American public has declined to bear aloft his image and his memory.