The best protection for beginners is instruction. For example, if all the benches had safeties, people would still have to know how to set them up at the right height, right? "Oh but that's easy, only an idiot can't figure that out." Yes, and only an idiot tries benching a weight twice as much as they've ever tried before while alone with no spotter. So whatever equipment you have, beginners need instruction.
But most don't accept instruction when offered (2/3 of new members refuse the free intro sessions, and 2/3 of those accepting them don't follow the programme given them, and 2/3 of those don't progress the effort as instructed), and if there were enough instructors for everyone, the gym would be too expensive for anyone. I mean the big place I worked at had 15 trainers and 4,000-5,000 members, I don't care how good you are, you can't instruct 300 people. 50, tops, spread through the week, and if everyone comes at scheduled times reliably - but then you'd need 6 times as many staff, and gyms would be $120pw instead of $20pw. And this assumes you can find enough competent trainers anyway.
It's one reason I just have the double garage with 20-24 people. No idiocy allowed. No bench with safeties, but nobody is loading it up with twice as much as they've ever used before, and there's always a spotter.
No doubt the boy's family will sue, and no doubt they'll win, because nowadays everything is always someone else's fault. So a place which over the years probably changed thousands of young people's lives for the better will close down because one kid was, as 15 year olds are, an idiot.