In my school, we usually have a speech or some other form of commemoration around Kristallnacht.
I have no problem with Yom HaShoah. Everyone should have a zman kavua to remember in detail, even if in effect we remember all the time. For those who won’t remember on Tisha B’Av, why not have their own time? If the alternative is that nobody will take the time to reflect on and remember it, then you’re shooting yourself in the foot by protesting.