I am very disappointed these days.

I'm afraid you're in for a lot more disappointment. You work so hard explaining things in a rational way, you use logic. For Heaven's sake, who listens to logic in the times of 'follow blindly whatever you're being told"?
As for the usefulness of statues, you are totally right. I was about to mention in this comment the news about a Catholic saint's statue being defaced in California. Before doing that, I went on Wikipedia and checked out this Saint Junipero I'd never heard of. Because this statue exists, I actually learned something today. Exactly as you say that Robert E. Lee' s statue won't make people approve of slavery, checking out this Junipero did not make me think "oh, the good old missionaries bringing religion to the pagans, who cares that they destroyed a whole civilization in the process.."
The funny thing is that not only the Saint was defaced, but also the little child next to him. Why would you paint a swastika on the statue of a child? This not a protest, it's pure vandalism.
And, of course, thank you for your support.