It is impossible to evaluate these monuments without considering the context of why they were created in the first place. Many of them were erected as part of the push to enshrine a dishonest, prettied-up version of the Confederacy—they weren’t a testament to our history, but a distortion of it.
Finally, if we want to learn about, say, Robert E. Lee—and we should—we can do it without staring up at a 60-foot-tall statue of him on a major Richmond, Virginia, thoroughfare.
We should make distinctions, of course. Big statues in prominent public spaces erected to make a point about the supposed glories of the Confederacy should come down and be transferred elsewhere (ideally to museums or battlefields). But this should always be done lawfully and with due deliberation, not via mob action or under mob pressure.
The Confederate flag should be shunned, as a symbol of a viciously flawed cause.