@omni-triforcer In regards to it being biologically bad for kids, that's not what this article states. Your point would have validity if this was an ongoing thing throughout one's family tree.
https://www.independent.co.uk/news/science/theres-nothing-wrong-with-cousins-getting-married-scientists-say-1210072.html
Also, there's this to think about as well. We're all technically cousins to each other.
http://articles.latimes.com/2013/may/07/science/la-sci-european-dna-20130508
https://www.quora.com/How-closely-related-are-all-humans