The anti-prayer tweets aren’t encouraging a debate about gun control; they are discouraging expressions of shock, sympathy, and mourning. That is, they are discouraging statements about the inherent value of the lives lost that address the real grief of the bereaved. Often that is the only thing we can sensibly offer in the minutes after awful news breaks across our screens. By discouraging these expressions, they are also inadvertently boxing pro-gun-control politicians into talking about the victims of mass shootings in a purely instrumental way, a less human way — thereby reducing such deaths to having no other public meaning beyond another reason to pass legislation that these politicians already wanted to pass. Without being able to offer a plain expression of sorrow and anger, even pro-gun-control politicians are deprived of a means of offering human respect before engaging in politics. This opens them to the charge of disrespecting the dead by using their deaths to promote views to which the dead would object.
So even if you are frustrated with America’s permissive gun rights, it isn’t the prayers offered to the dead that are the problem. Let people mourn the dead. Let them say the human thing first. And then engage in vigorous political debate afterward.