My actual feeling is that those who would celebrate a public execution would see someone getting shot to death and think the ordeal should have been much more spectacular.

Years ago I was an EMT student in the ER when someone came in with a nasty case of multiple gunshot wounds to the hands, arms, legs, chest and abdomen (shot in chest through hands in defensive posture, then shot repeatedly while on the ground including in the abdomen via thighs as they curled into a ball).
There's no explosion of gore or dramatic Hollywood effect. The people watching the execution will just see something similar to getting poked by a giant needle and then going limp.

They won't celebrate because they'll be disappointed there wasn't more.