Even though I am aware that others seem to view the matter very differently, I'd like to say what I think about the business of guided wildlife photography (and about funding it as a customer).
What Bjørn said at the beginning is certainly true.
There are obviously a wide range of offerings, some more "natural" than others, to the point that some almost guarantee to deliver whatever they promised, but in general it is fair to say that "aided" hide photography and photo safaris have lost their originality long ago.
For many of these activities the customers should not fool themselves that they are experiencing the real deal, they are not. Also for those who would like to use the images professionally, care should be taken in presenting them; the ethical position should be that the photographer does not claim what these images are not, nor, by omitting information, let people/customers draw erroneous conclusions wrt the conditions under which the images were acquired.
However, most people taking these trips are not professionals and they don't have time or skills to immerse themselves in truly wild natural environment to acquire these images (and experiences) "the hard way". But they still would like to have something as close as practically possible to the real deal, and I see nothing particularly wrong in that.
At least, no more wrong than wanting to buy expensive glass that will not make their photography improve, or fast, expensive and polluting cars that are not 10 times better than cars that cost 1/10 the price (the list of examples could go on... expensive wines, and all sorts of status symbols).
With the years I have become less excited about images of wildlife (including my own) but I would still feel the thrill of being able to see and photograph macrofauna about their business (and especially apex predators), even if I am aware that the experience is somehow manufactured.
Regarding those that offer varying forms of wildlife photography as their business, I would think twice before casting sweeping negative moral judgements.
I agree that times have moved on and zoos are questionable in terms of ethics. People in favour may still have valid arguments in their support, but I think the general sensibility is shifting against them. Personally I don't find interesting shooting animals behind bars, but YMMV.
However this conversation is not about zoos, it is about businesses that offer clients the opportunity to see wildlife in their environment.
These businesses are certainly bringing humans closer to relatively intact wild places and doing so they are perturbing them.
But what are the alternatives? There are essentially no more truly wild, pristine places in the world. Even places that don't see wildlife tourists aren't truly free from Humanity, just think about all those remote places in Northern Canada and Siberia, or the Amazon, devastated by huge mining operations. Humans are growing in numbers enormously and many wildlife-rich places (Southern and Eastern Africa are prime examples) are under enormous human pressure (including man-made climate change, which affects profoundly places that hardly see any humans). In these places wildlife and the environment in general are under more pressure from other human activities and lucrative businesses like wildlife photography can actually have a net positive role in conservation, for example taking an active role against poaching and providing economic alternatives to more unsustainable exploitation of the territory.
Going back to what Erik said last, I would not mind some wildlife friendly NG event in the future, if I can fit it with my work and family.
Europe is better for me simply on the grounds that I have to travel less far.