Don't have to sue if you have a well written contract, they either make it right, or then the suing starts. In this case, they probably had a clause about part source being up to the OEM as long as they met the technical requirements. That they turned out to be subpar is really on the component manufacturers. (Though one would have thought significant testing would have been done, or at least sampling, to check for failure rates on the finished product)
Business sense > common sense when money is involved. They don't want to take the loss, so they are pushing their vendors to sell the things despite the negative press. That Newegg, in particular, goes along with it is pretty stupid, but then again they have become a marketplace of crappy products. I knew it was bad news when they started selling appliances...
My guess would be Gigabyte set a price target and left them to it. Gamer's Nexus also mentioned that part availability may have been a driving factor. Shortages everywhere, if they had to use three or more sources for parts to meet the delivery schedule, that is what they had to do.