Line breed is different then hybrid. I am not going to get into the whole thing. Search around if you want. A key element is the young of a hybrid will not always look like the hybrid. (IE maybe 25% will, but the other will be split looking more like mama, or papa of the they hybrid, causing people to sell those contaminated fish as what they look like rather then always hybrid.) Line breeds on the other hand always look the same as there parents.
My personal belief is that I enjoy hybrids. I keep them but don't breed them. I think they have a purpose in the hoby to get more people interested and into it. I also think that we need to have a solid base of people who keep there fish as close to the original as possible. (Even though that is next to impossible.)