Statues don't teach history, they celebrate it. Take them all down tonight and the history will be there just fine, in the schools and libraries and museums.
A statue in the town square is a commemoration, a statement that this is the person we want to emulate, and wants our kids to idolize. I think we as a people have moved beyond wanting our kids growing up wanting to be just like Nathan Bedford Forrest.
How about Robert E. Lee? Nathan Bedford Forrest was a better man than Abraham Lincoln.
Regardless of his 'Southern Gentleman' persona, Lee still took up arms against the United States in order to defend the institution of slavery. Personally, I don't particularly want that glorified in my town square.
Also, your second sentence is, to say the least, a minority opinion.