Another aged ex lifeguard here. I volunteered for 30 years, and am still involved with the club. It's been an amazing hobby to have with a most excellent social aspect!
Great to see that the RNLI have stepped in.
IME a lot of the work as a lifeguard is preventative, so warning people before they get themselves into danger. Of course some will ignore you, spit at you, or abuse you but the vast majority will do as asked/suggested and stay safe. I don't know this beach but it might be that had there been lifeguards there they would have been able to warn them or get to them sooner.
The other thing is that a lifeguard service isnt just there focussing on the water. Eg they provide first aid, deal with lost children, incidents on the beach and even if this were a relatively "safe" beach, with the numbers going to it I would have thought on a beach of this size there was a need to have guards there.
I agree totally, there is a need to educate people about respecting the water - and it's not just at the beach, there's inland open water, swimming pools, ponds, baths. All water is a hazard. And charities like the Royal Lifesaving Society, RNLI and Surf Lifesaving do an excellent job with their community programmes and clubs all over the country.