Yeah, a lot of people don't seem to get that boxing is GREAT for street fighting / self defense, for a variety of reasons (timing, footwork, distance, proper punching, reflexes, head movement, getting used to taking shots, conditioning etc). I was a bit of a hothead in my youth and experienced first hand, several times, how effective boxing can be. It did more for me than perhaps anything else (with years of training, mind you, and eventually 39 fights in the amateurs). A few times a street fight would honestly feel a bit like a joke, like I hadn't been in a real fight at all, because an untrained opponent would be so fucking slow compared to what I was used to with my sparring partners etc that I almost feel like I'd cheated. Like my adrenaline had been pumping like crazy (it usually did) for... nothing. And I've known plenty of boxers who said the same thing.
By itself, though, boxing is just highly incomplete. To argue that boxing prepares you better for the street than MMA does, with enough proper training in both, would be beyond ridiculous. For me, it was only after I also started training BJJ in the mid nineties that I really felt confident that I would not get my ass kicked in a one on one confrontation. Because I always knew that boxing, as well as the traditional martial arts that I'd trained, would do fuck all for me if the fight ended up on the ground, and fights obviously often did. Boxing does work very well when you're standing across from someone with enough distance between you, but fights don't always start like that, and they very often don't end like that either.
That said, I still find myself telling people to start in boxing, at a good gym and with a good coach (which can be hard to find, admittedly). Just focus on that one thing for a while (which is of course more than enough). Then, only when they've got some basic skills down (which probably takes a couple of years, if they're still doing it - most people obviously won't be), start adding in the other stuff. It's a much better way to go than starting everything at once, like a lot of people are doing these days. Real focus is so incredibly important, whatever you're trying to achieve some level of skill or success in. And the problem with a lot of MMA gyms is that they try to teach too many things at once. That's a terrible approach IMO, and I say that after some 33 years of doing all this fighting stuff. Ideally, people should start with one thing. And I recommend that one thing be boxing. Two years seems like a terribly long time for a fifteen year old kid who's getting into fights, though, so a bit of a compromise with some BJJ or wrestling training here and there might be the way to go. And learning enough BJJ for it to make a meaningful difference in your ability to defend yourself does NOT require a big time investment anyway. Far from it.
Whatever they do, they might of course still get shot or stabbed or jumped by eight guys when they're all alone. Life sucks.