To directly answer your questions:
- YES it is unusual to erect war memorials in honor of the losing side that was defeated. (Especially when that side was treasonous.) Go find a country that has erected memorials, monuments, statues and waves the flags in honor of the country IT DEFEATED. Doesn’t happen. Those go in MUSEUMS.
- Angry mobs have torn down memorials and statues that honored leaders that they found to be oppressive or insulting. Saddam Hussein had his torn down to cheers. Idi Amin and Mugabe had theirs ripped down by mobs too. Black South Africans have also angrily torn down statues of FW deKlerk after apartheid ended and Mandela was freed and elected.