Is it any more sick (I realise 'sick' is a synonym for 'good' with those pesky kids) than Call of Duty? There's some veterans of D-Day who are still alive.
JFK assassination is a very strange phenomenon though. I know it was an absolute huge event but I think it's mainly a combination of the Zapruder film (which has given me the creeps ever since I first saw it on the shoddy - although I didn't know it was at the time - documentary 'The Men who Killed Kennedy' - made for the 25th anniversary in 1988), then Oswald being shot live on TV only a day or so later. Then of course you had Oliver Stone's completely ridiculous but thoroughly entertaining film and finally the internet which seems to absolutely thrive on anything conspiracy based.
I think Oswald did it and he probably acted alone.