I'm not a real knowledgeable in the realm of shotguns. I own a Stevens single shot 20ga. that I believe doesn't have the same actual recoil as a 12ga. It is much lighter than your typical 12ga. and probably induces a sharper felt recoil using heavy loads. It still isn't much of one for me anyway using factory loads. With that, these are my points/counterpoints to the discussion:
1. They're usually so inexpensive that it's hard to turn down buying one, especially if you're on a tight budget and/or just starting out.
2. As said before and mine as well, it's very light. For those in the know regarding skeet, trap, hunting, etc, I'm thinking this could be a blessing or a curse. I find it a blessing for the beginners and kids. I think trying to heft weight around causes fatigue to set in for this demographic. They already have enough to worry about. It's a distraction that isn't needed at this point.
3. If you're a reloader, the argument of it being as much recoil as a 12ga. can be quelled...sort of. The same argument can be made on reloading for 12ga. as well. My point is you can tailor to your needs/wants by reloading which goes without saying.
4. It can compete with a 12ga. on most fowl and varmints up to the size of a coyote. Not saying all game nor is it better. Just saying it can do more than most think...
5. And last, yet most important in my book: SAFETY. No matter how much you think you taught your kid or beginner on safety, they just might not have that ingrained in their head. No matter what, once that first shot is spent, it's not going to go off again if they forget about trigger control. Had a friend that took his son out to learn how to shoot a shotgun for the first time. Handed him a semi-auto (don't remember the model). He aimed at the target, shot a great pattern, and with pleasant surprise the kid turned around with a surpised/excited look on his face from a job well done. Well, as he turned around, so did the shotgun. Fortunately, it was only half-way around before he performed a negligent discharge and he had it pointed down. Kid had enough punishment, though. Had to eat through a straw for the next 4 months while his mouth was wired shut.