No, I would not like a ball-pit in my workplace. There are many reasons for this:
1) The pit would be ridiculous to clean. Children will probably piss and puke all over and considering I'm on the lowest rung of the ladder, it would be my job to clean it up.
2) My workplace already has a lot of children running around at any given time. The pit would only attract more.
3) The balls would get everywhere. I'm a pretty clumsy person so I'd bet that I'd slip on them pretty often, especially when carrying something heavy or fragile. I really don't want to get injured right now and I especially don't want to ruin something valuable and/or important.
And most importantly:
4) I currently do not have a girlfriend to f-ck in it. That's the only reason I'd want access to a ball-pit: to mimic the XKCD comic.