I will say, however, that there are ways to pander to the species visitors "want" to see without homogenizing, as oftentimes it's larger taxonomic groups visitors care about, not specific species. Furthermore, I'm of the opinion that, while it is important for zoos to include some popular species, I'm not convinced that they need every single popular species. As long as a zoo has one or two species of big cat, very few visitors will be disappointed that the zoo doesn't have lions AND tigers AND leopards AND snow leopards AND jaguars AND cheetahs, so on so forth. Plenty of zoos have been very successful without exhibiting all of these species, but zoos do benefit from having big cats. Same thing with bears, visitors want to see bears, but don't necessarily care which species of bear it is. Likewise with great apes, elephants/giraffes/rhinos/hippos, etc. Having these are great, but a zoo does not need all the popular taxa- visitors would be disappointed if they paid money to go to a zoo and there's only ten or twenty popular species, those other species add interest to exhibits and increase the duration of visits, making the visit seem more valuable to visitors.
One example I'd like to mention for where zoos need to do a better job of balancing popularity with homogenization is primates. Most zoos exhibit some sort of primates, and that's great as most visitors do enjoy seeing monkeys or other primates in zoos. However, visitors don't usually care what species of monkey it is, and may even prefer seeing different species than their home zoo (i.e. "I've never seen monkeys like that before"). Furthermore, by different zoos keeping different species of primate, it can provide more interest for those who do visit other zoos, as they get to see different species in different places, rather than every zoo having siamang, black-and-white colobus, debrazza's monkey, pale-faced saki, ring-tailed lemur, and cottontop tamarin (six of the most common zoo primates).
Likewise this could be applied to hyenas. Zoo visitors want to see large carnivores, but zoos can provide variation within this group, and still be appealing to visitors. Rather than every zoo holding grey wolves, it'd be better if some held grey wolves, some held red wolves, some held maned wolves, some african wild dogs, and some choose to exhibit hyenas instead of a large canid. Furthermore, if we add felids into this mix, some zoos should consider, rather than house lions and tigers, house one of these species and then a different type of large carnivore. For instance, a zoo may choose to keep tigers in their Asia section, but then instead of lions, their Africa section could include African wild dogs or a hyena species. There is a limited space in zoos, and not all species can be kept, but zoos can do a better job of equitably distributing that space to the species/programs in need of space, while still appealing to the wants and needs of visitors, as well as the educational and research needs of the zoo.
