Nobody is arguing that adoption per se isn't the same as "the same family". The practice being described here is that the adoption is specifically adopting someone _because_ they're going to be the next owner of the business. I'm sure you can see that there's a salient difference between your case of adopting to build a family vs the case here of a 65 year old guy adopting his 50-year old successor as part of a tradition of that business.