@CheeseChameleon2007 I'd say the reason is that both Zoos and Lego's main demographic are younger children, so it makes sense for zoos to have things that'll entertain younger kids apart from the animals.
Personally I've never had much interest in Lego although I do think some of the lego animals in zoos are pretty cool.
@TZDugong Thats understandable. I was a huge lego fanatic when I was younger, I saved up all my money just to buy lego sets and that's it. A couple years ago I stopped because I simply had too many, and I had enough pieces to work with. I also remember going to my grandparents house and playing with legos from the 80s, such good memories.