Unfortunately, we live in a litigation obsessed culture (I blame US-style cable TV ads). This is the authorities just covering their rears in case some twonk does just that, falls, injured etc & blames council. Personally speaking, anyone who goes up and sits on one, then falls and is either injured or killed, that's just their own fault & could be seen as evolution at work, weeding out the 'I am an idiot' gene from our DNA. Go and take a look at the Darwin Awards for further info.
I would also recommend the very funny Armstrong & Miller sketch about an accident claims hotline for actors who injure themselves while filming accident recreations for insurance claim lines......
Perhaps people don’t realise quite how high, hard to sit on and slippery the lions are. Perhaps so many people try to do it and the injury levels are so high it’s worth pointing out that you really shouldn’t as it’s dangerous. And finally, perhaps because most visitors to TS are not native English speakers that a clear visual image is the best way to communicate this.
Alternatively, blah blah Daily Mail ill thought out moan it’s flippin health and safety nonsense.
I made a jokey remark about 'Health and Safety gone mad' on a ride with @Littgull once, not realising that that was his field of expertise. He soon put me straight with some horrific stories of what can go wrong when people don't take H&S seriously!
So, yes - spoiling the fun of young drunks climbing onto the lions, but saving their parents the trauma of having police officers knocking at the door in the middle of the night to give them tragic news?
(Not that anyone who wants to climb one of the lions will take any notice of the warnings!)