When I was young, we knew the beaches were dangerous, rocks could fall from the cliffs, the tide could be treacherous, dog poo in the sand was a bad thing (not as bad as the tear off drink can tabs!), and the rip current would drag you off, and as for jumping on to the submerged rocks - well that was just stupid!
But now it seems people who come to the beach are ignorant, and the threat of liability for their own ignorance or stupidity (inflatables are dangerous - no **** sherlock) results in eyesore signs like these.