Unfortunately, in the process, you end up hurting not only the pests, but also the beneficial organisms that you should be encouraging. Moreover, many chemical pesticides can cause serious medical problems for family members and pets if used on a continuous basis or in large enough quantities.
Why take chances? By utilitzing organic plantcare methods, you can maintain a comparable level of pest control, while achieving better yield and, just as importantly, a much lower level of health hazard.
It's not easy, but with the correct understanding of organic methods, anyone can be an organic gardener.