If we genetically modify our kids there would be no need for medicine or doctors. (other than genetic ones) We could be immune to numerous diseases and disabilities. No more cancer, Alzheimer's, or AIDS. We could live for longer, think about that we could live for more than 100 years! We could make diseases die out and the world be a safer place for out children and ourselves.
Parents should screen for desirable genetic traits in their offspring as this will yield a higher probability of the parents having a child that has desirable genetic traits. Science can help build a better society through methods such as this one, and the option and encouragement to practice such methods is appropriate.
If we had fewer birth defects, we would have a healthier general population. A healthier population generally gets more done. Not to mention, if less is spend on medical care of those with undesirable traits, then more can be spent on consumer goods, and projects that benefit the human race as a whole. I hope we reach a day when we can rid ourselves of the worry of imperfect offspring.