Abso-fucking-lutely. The ability of this and similar weapons to be used by completely untrained maniacs to deliver very large numbers of death within seconds is its main draw. The Vegas shooter (self-trained) was able to shoot 1200 rounds in 10 minutes, killing 60, wounding 413. The last few shooters have been young, completely untrained and unhinged young men. Below are just a few off the top of my head. I'm sure I've forgotten a few. In the majority of these the killing happened rapidly, within minutes. It, and similar weapons are the weapon of choice for mass murderers for this very reason. The rate of killing ability of these weapons is one of the reasons WHY we have active shooter training. The response has to be quick and decisive if any lives are to be saved.
Highland Park (age 21) (7 dead, 46 wounded)
Uvalde (age 18) (21 dead )
Buffalo (age 18) (10 dead, 3 wounded)
Parkland (age 19) (17 dead, 17 wounded)
El Paso (age 21) (23 dead, 23 wounded)
Sandy Hook (age 21) (26 dead)
Aurora (age 24) (12 dead, 70 wounded)
What the AR-15 does to the human body
See how AR-15 style guns create 'explosions inside the body' - YouTube
What Happens To Your Body When You're Shot By An AR-15, VICE on HBO, Season 6 - YouTube
6 yr old shooting AR-15
Child Shooting the 3-Gun AR15 at 100 Yard Steel Targets - YouTube
7 yr old shooting AR-15, note that she is only holding the trigger with the gun propped on a bag
7 Year Old's First Time Shooting AR-15 - YouTube
ETA: Fixed Highland Park