If the principal purpose of a bump stock is to send bullets downrange at a higher rate during recreational shooting, then why don't we permit the wide ownership of full-auto machine guns to send bullets more rapidly toward the target at the range? It's only about target practice, right? After all, guns don't kill; people do.
Let's for the moment take off the table criminals with malicious intent. If we look only to crimes of passion, where in the heat of the moment an otherwise good person snaps into a murderous rage, a gun ready to hand makes killing so easy. The up close and personal, effort-requiring, messy and potentially dangerous to self knife attack will give more folks pause than will the less intimate, stand-off, near zero effort of pulling a trigger.
Curb access to guns and the homicide rate will fall precipitously. Most of the rest of the world has already figured this out. It's utterly senseless for there to be all kinds of rhetoric about foreign terrorists so as to keep Americans safe--God forbid that a single citizen be slain by a 'Muzzie'--while there is such apathy regarding the annual harvest of many thousands (including children) by your own hands. That's a double standard of ludicrous proportion. "Only Americans reserve the right to kill Americans, and we'll die defending that right!"
