Why do you think we're being judgmental? We're giving our opinions about the topic that you posted and doing it nicely. I haven't seen anyone condemning people that linebreed and while it is something that most people are ignorant about, there are going to be a variety of opinions about the topic. I am also curious about how breeders handle linebreeding and why they do it and what sort of results they want/can come up with. But I also think it is better to mix blood as often as you can while still doing occasional linebreeding because it helps the genetic pool stay healthy.
But it is "taboo" for a reason, it's unhealthy if done too much or too closely. Cheetahs, for example:
http://lynx.uio.no/jon/lynx/cheetahgenes.html
So naturally people believe it is something to avoid to keep animals healthy.