I didn't really mean to complain as much as wonder why the uploading tendencies had changed so much during ten years.
I'll admit it's a bit annoying when you're curious about how a zoo's exhibits look like, and you only find page up and page down with close-ups, but that is rarely the case - if a gallery has a lot of close-up photos, it usually also has a lot of exhibit photos.
I like viewing good portrait photos as much as the next person, but a slight issue I take is that if the photo is so close up that you can't see anything of the surroundings (i.e. exhibit), then it doesn't have much value as a zoo photo despite that it might a good portrait photo. So if you're uploading photos of a well-documented zoo such as Chester Zoo or Zurich Zoo, I don't really mind close-ups since there are already photos of every noteworthy exhibit there. If you're uploading photos of a zoo that has none or extremely few photos in the gallery (for example Tierpark Suhl or Wingst Zoo), it might be more relevant to us zoo nerds to upload exhibit photos first.
Anyway, as Sim states, there are no separate galleries for close-ups (because the line betwen portrait and exhibit can sometimes be hard to draw), there are no rules against it, and loads of other users only or mostly upload close-ups, so just upload to your heart's content. (As long as you're following the general upload rules, of course)
Thanks for your balanced and thoughtful reply, @Hvedekorn.
I think most of the zoos I have been able to visit and photograph at are fairly to very well-known zoos and facilities in Belgium, the Netherlands, western Germany and northern France, and most of them are bigger, well-established zoos that are already well-known and well-documented in the gallery.
Also I have in fact added quite a few exhibit photos from a few of recent visits (and am adding more at the current time also) and I am planning to post more exhibit photos from my local zoos (Antwerp and Planckendael) in the future. Personally I prefer to post a mixture of animal and exhibit photos with a few botanical oddities thrown in on the side and some photographs of signage to complete the story of a zoo. I don't see at this point much reason to change that, at least not as far as recent photographs are concerned.
I have actually visited a few smaller facilities that may not be as well-represented on this site yet, but those visits happened some time ago so I'm not sure it's very relevant to post old exhibit shots, or if it would be fair on the facilities to do so.
It's still a plan for the somewhat distant future to go through my old stuff as I've still got recent stuff to sort through, but at this point I think I might just go ahead with it.