Well, to be fair, it seems you have taken a photo of the most unusual bench in the zoo! I do agree, these new benches are quite hard to sit on, but you just have to look around, and "try" to find the most bench like structure.
Whilst at the Zoo, I heard quite a few good comments on these Benches, and I too like them. But Im not going to use them!
Are benches that are hard to sit on a bit of an oxymoron? We're both in the prime of our lives (!) but I wonder what use they are to people with frailties, the elderly and overweight? The traditional benches are hidden from view - and face the wrong way - so people miss them, and it's quite a walk to the next nearest.
For what it's worth, my mum (a zoo member) has three replacement joints, but although she's remarkably fit I hear a lot about the need for more places to sit down and I'm sure she wouldn't risk one of these!