Oh, there are plenty of people falling all over themselves to tell stories about Grant that leave a favorable impression. But stories that reflect poorly on his character get swept under the carpet. He is the 21st century version of the marble man.
For example, there's evidence that he may have been a beneficiary of illegal cotton trade, although most hagiographers (calling themselves biographers) represent him as an opponent of such commerce.
But it has recently been discovered that he sent an officer to collect a report of an investigation in cotton trade in the western theater when he was a top commander there. After Grant's staff officer collected the report it was lost to history. The officer who tuned it over did so with great reluctance because he feared it would get "lost." That apprehensive officer did not survive the war.
Meanwhile, it is known that Grant's brother-in-law traded gold for cotton against regulations and was given a permit by Lincoln. When Grant later asked Lincoln to suspend such trade east of the Appalacians, Lincoln told Lamon that: He (Lincoln) was surprised at Grant's attitude because the general awarded one of earliest such permits, and that to his own father.
Admittedly, none of above is proof that Grant benefitted from cotton trade, but the point is that almost all biographers and civil war commentators ignore it...because he is the marble man.