This statement is not supported by the research. In fact, generalist species are often not as good at any one thing as specialist species. For example, a generalist predator may be able to eat a variety of prey, but it may not be as efficient at hunting any one type of prey as a specialist predator. Similarly, a generalist plant may be able to grow in a variety of habitats, but it may not be as well-adapted to any one habitat as a specialist plant.

Therefore, it is more accurate to say that generalist species are "jacks of all trades and masters of none."