With all due respect to the concept of "a football move", there doesn't seem to be much doubt that rule makers, and everyone else, recognize that any use of the head, to deliver any kind of blow, is probably the most dangerous thing any football player, on offense or defense can risk. The type of injuries possible are simply too horrific to ignore. Probably 80% of the "Points of Emphasis" over the last 10-15 years have related to eliminating some type of contact using the head to block, tackle, or spear.
The fact that someone who can never walk again was a runner, rather than a defensive back, doesn't seem to make much of a difference. What Earl Campbell did was "then", this is "now". Rules have evolved over the years to require face masks and helmets, that were once optional. The "Flying wedge" was declared illegal, although it was often effective. "Chop Block" is no longer legal, because it was deemed too expensive, as was traditional blocking below the waist. The game evolves, as do the rules.
"Lowering the head", to gain additional yardage and using the head to batter, bash, butt a potential tackler are two different things. If you can't tell the difference, or can't explain your logic to a coach, parent or anyone else who can't understand the difference, maybe football is not your game. All that really matters is that officials understand and appreciate the difference, and have the guts to do what is right, rather than be at all concerned about what others, who are wrong, think.