How stupid of some/most Brits to even think this.
The monarch IS NOT HOLY.
It's not a question of "holiness" but of decorum-- a sense of order and fittingness and a time and a place for everything. It's something the office of the monarchy and other institutions like the military, etc., are built upon, even since the early years of our Republic. That's why we salute the flag and treat it with respect, for example. It's something we've lost a sense of and our culture is the poorer for it.