I think it's fine for:
- Robert E. Lee (and other Confederate leaders) statues to still stand in the US
- Lenin & Stalin statues to still stand in Russia (and other ex-SSRs)
- Mao statues to still stand in China
- Mussolini statues to still stand in Italy
- Hitler statues to still stand in Germany
You may argue that Lenin, Stalin, Mao & Hitler were horrible people - and I agree, but my point is that removing historic statues & symbols is an attempt to erase (good & bad) history. Said erasure will cause the next generation to be more likely to repeat the bad history because they are too ignorant about it.
I will say that it is concerning to me when a statue of a foreign evil leader is in a different country than that leader is from. An example: Lenin statues in the US make me concerned, as that would not be about history - but can imply dangerous political aims (communism in that case).