Who's saying don't adopt cats. You should totally adopt cats, cats are amazing pets, adopting from a shelter is the best place to get one. Spay neuter programs are the best way to control feral populations since there is no way to eradicate feral cats while allowing pet populations. Pet populations will ensure feral cats remain endemic forever.
That doesn't stop that the entire issue of feral cats and pet cats are linked, and also linked to bird predation. The US as a society has chosen pet cats over wild birds. Some other nations handle by culling, like Australia, or new Zealand now.