You must be a right-winger - presented with facts, you opt not to educate yourself, but to dismiss it with a bullshit phrase like "pseudo-intellectual" (the actual meaning of which is clearly lost on you) because it's inconvenient.

Look, I have a seven-year-old. I took him to the zoo last summer, and he got to pet goats, feed rabbits and chickens and whatnot, and come nose-to-nose (through glass) with an otter that was just as curious about him as he was about it. I love watching him interact and learn. When we were in the primate house, though, there were different expectations.

One of the biggest challenges for zoos that keep primates - the great apes in particular - is keeping them mentally healthy. They are intelligent, with complex social dynamics, and as I said before, they are unusually sensitive to the behaviors of the humans that are constantly stopping by to watch them. Behavior that to us is relaxed and happy is often very unnerving to them, and long-term exposure to that makes the apes highly susceptible to mental illness, including anxiety, depression, aggression, and self-mutilation. This is fact.

When my son and I were in the primate house, we - like everyone else, at the request of zoo staff - moved slowly, spoke very quietly, stayed back from the enclosure, and avoided eye contact with the gorillas and chimps. It's not being a killjoy, it's having respect for the animals and their caretakers. Allowing him to run wild in there would have been just as inappropriate as allowing him to throw rocks at the tigers, feed cotton candy to the giraffes, or bang on the reptile cages. It's harmful, and not okay. Once we moved on to the rest of the zoo, he got to run around again. But not there.

In the linked .gif, the baby may or may not have been playing - it's hard to say for sure - but even if it was, the mother was clearly distressed by it, and that is a very real issue with these particular animals. A refusal to acknowledge that only reveals either ignorance or callousness. Don't be stupid, and don't be an asshole.