Zoos at the end are just a profit making business. Some may advertise conservation as their agenda but at the end, when a consumer is paying to enter and be entertained by the animals, the welfare of the said animal generally is given the least consideration.
We have been born into a society that accepts animals in zoos as commonplace but the invention of the zoo dates back thousands of years — to an era when people who looked different were also put on display. We now have unlimited options for entertainment, not to mention a greater understanding of animal sentience and needs. In today's society, ogling at animals in zoos behind glass seems crudely outdated. Certainly it's unnecessary and rarely (if ever) in the animals' best interests.
Let's recognize this as an inhumane practice and stop putting animals through lifetime of torture for our momentary entertainment.