imvho, that fine line you're talking about comes in the form of stability, which we all know was never a hallmark of tga's gear.. taking a polyhybrid and crossing it with another polyhybrid and slapping a name on the out come if far from breeding, again, imvho.. if you take a ten pack of beans and get 5 very distinct looking plants out of 10, well, that's not the definition of true breeding. i think most people will admit that an f1 isn't really ideal for stability..
what home brewer was trying to say, not that i want to put words into his mouth, is that anyone can take two plants, slap some pollen on a female and get half way decent seeds, but it takes someone with a lot of knowledge, and willingness, to take an f1 and work the line looking to refine certain characteristics and create a stable strain..
an example of this would be let's say ak47 from serious.. you could probably crack 100 beans and get 90 very similar looking plants.. an ex. of the other way would be let's say plushberry.. i've heard of the pink pheno, the green pheno, the this pheno, the that pheno, it's simply all over the place.. this is not to say it's not good smoke, it's just not what a lot of people would consider stable, or good breeding practices is all..