It’s fiction. Despite years of research that can find no evidence of any harm from feeding wild birds and studies showing birds use feeders for only about 25% of their diet, the myth that feeding wild birds will make them too lazy to find food still persists. According to the Humane Society of the United States, experts still disagree about whether feeding backyard birds will increase bird populations overall; however, they say feeding birds can certainly help the birds in your neighborhood. In fact, the Humane Society encourages people to feed wild birds, especially in the winter. Below is advice from the Humane Society of the United States website about placing feeders.
Birds are most likely to eat where they feel safe from predators, including free roaming cats. Place feeders twelve feet from a brush pile, evergreen tree, or bush. Birds can quickly fly twelve feet to reach the safe cover, yet predators cannot use it to hide within striking range of the feeder. As further protection, place chicken wire or thorny branches around ground-level feeders.