While this sort of thing is not to my taste, a lot of things in society aren't, these days. Without seeing what the target in question actually looked like, it's hard for me to pass judgement.
But there has been one major change on the issue of guns since we were all growing up - we now have a Supreme Court decision that CONFIRMS GUN OWNERSHIP AS AN INDIVIDUAL RIGHT BASED IN SELF-DEFENSE - not a collective right based on military service, or "hunting." That is absolutely huge.
Part of what that means, is those of us who grew up in the 60s, 70s, or farther back, need to not be so attached to our "sportsmen and hunting" cultural concept of gun ownership. That is not what it is about any more, whether you like it or not. That may be what you grew up with. But it ain't what it is.
The nominal, statistically-average American gun owner is no longer a hunter. He/she is a handgun owner and CCW holder. And I for one am glad to see this change. Let's get it right out there, and be frank about what guns were originally invented for. They are martial instruments first, sporting tools second. In my opinion, the hunter/sportsman cultural theme did a CRUMMY job of protecting gun rights, and we might as well admit that, and sever ties with it. The idea that the Second Amendment was about hunting was easily-manipulated by the Left, and the historical cultural attachment of gun ownership to hunting, sporting, or whatever did nothing to prevent the Assault Weapon ban when Bill Clinton signed it into law. It actually helped it, if anything.
What changed this past time around, was shall-issue CCW in 49 states, and a legion of newly-minted gun owners in part because of it. When you make gun ownership personal and relevant to the urban and suburban citizen, you take it out of its stranded rural cultural context, and make it harder for the Left to marginalize.
The potential to use guns to defend yourself is now recognized in Supreme Court case law as what the founders were trying to ensure when they wrote the Second Amendment. Let's roll with that. I'm not crazy about what you described at the range, but I'm not prepared to throw up the red flag, either, as long as they're being safe. A whole lot of parents are teaching their kids a whole lot of irresponsible and/or harmful things that don't involve guns in any way. Shooting "bad guy" targtets with guns? Meh.