Scientists cite how the offspring of 2 blood-related parents has a higher chance of suffering from birth defects. [...] Likewise, there is no legislation prohibiting people with hereditary health problems or birth defects from procreating, which seems to smack of double standards.
Scientists are not the ones creating and passing bills, even if they have some influence.
Also, just because someone has a defect does not mean they will pass it on (even if it is likely). To compare inbreeding with the procreation of those with defects is like comparing apples and oranges. They're both fruit, but they're quite different.
Also, having your "tubes tied" only has a 90% efficiency (that is, it is 90% likely to prevent a pregnancy). A vasectomy has a 99.7% success. Condoms, of course, for a variety of reasons, can be unreliable.
I'm not arguing for or against "incest" (myself not having quite formed a stance just yet), but merely putting forth some relevant information and playing devil's advocate, as always.