HI Frank,
Actually, they are right. The vast majority of birds have almost no sense of smell or taste. (the exceptions being carrion seekers like vultures). The main birds that people rescue are the passerineformes (finch/sparrow type birds), and they have the weakest olfactory lobes of the birds.--these are also the ones that people seem to associate with abandonment and smell since they are the ones that are "rescued" the most.
In fact, birds rely primarily on sight to find food, and birds have a preference for certain foods based on their textures and colors, not their taste. (I mention this because we all know how dependent on smell that taste is) You should see my parrots feed! I will give them a pelleted diet that consists of yellow, red, green, orange, and purple pellets all mixed togeather. The next feeding, one cage will have all the green missing, the next cage will have all the red missing, the next will have the red and yellow missing, the next will have everything missing except for the yellow, etc.---It's not the most hygenic, but I swap food bowls between cages to prevent waste and so they can eat the color they like!
It is believed that the parent birds visually seeing someone touch their young is what causes them to abandon them, not scent.
Smell
As the large optic lobes in the brain indicate the importance of vision, the reduced size of the olfactory lobes indicate the lesser importance of the sense of smell. The olfactory lobe is smallest in passerines and parrots, intermediate in pigeons and gulls, and largest in water birds (e.g. ducks and loons) and the Brown Kiwi. In fact the Brown Kiwi is the only bird with nostrils at the tip of its beak. This bird is nocturnal and has very poor eyesight. It finds buried food by sniffing for it. Vultures will congregate at the smell of carrion. Pigeons have a good sense of smell and use it for navigation over long distances. Some ocean birds (e.g. petrels) navigate back to their islands and nests by sense of smell.
Taste
Birds don't always share human tastes. Some things we enjoy they may find offensive, and vice versa. Birds can distinguish tastes, but with less acuity than mammals. This can be explained by the number of tastebuds present. A parrot may have 300-400, a kitten 473, a rabbit 17000, a human 9000, and a snake zero.
(The snake argument kind of throws a monkey wrench into the argument because we herpers all know how acute their sense of smell is, while they don't have any sense of taste at all!)
http://www.silvio-co.com/cps/articles/1998/1998roscoe1.htm
Rodney