This guy dying is akin to the breakup of the USSR or the Berlin Wall for some people. He wanted to be a symbol, bigger than a human being, well, he got it. He became an archetype of fear and oppression and to rejoice in something like that being gone is A-OK in my book..
This is were I have an issue. I have several uncles (all now deceased) who served in WWII. My father (also deceased) climbed into a B-17 and flew 35 missions over Europe. My brother served 30 years in the USAF, retiring as a Full Colonel. I never served as there was this Vietnam thing I (and my father) disagreed with, but I declined an Academy appointment and acted against that war.

There is a famous picture of an East German Border Guard jumping the barricades for freedom during the cold war.

There was no celebration of Hitler's death that I know of. There was a celebration of the end of the war. We aren't there yet.