It's funny. Here in Australia we seem a lot more relaxed about breeding LFS bettas. Heck, one of my favourite spawns ever was done by someone with a VT female and DTVT male. That spawn produced a lot of healthy fish who might not have been show quality but made for beautiful pets.
I wonder if it is because it is rather expensive to get in decent stock here and that most stores really don't carry the quality you guys seem to get from your Petsmart and Petcos that there is less stigma involved. I mean to import a betta from AB you have to pay for the betta and then pay I think $22-$27 a fish
to get it into the country. Then they have to stay in quarantine for seven days. After which they are released and you pay for the shipping if you do not live near the store. Only one store here in Australia actually offers the service of importing AB fish in. She almost stopped doing it for a while because some doofus imported like a hundred guppies in without realising they had to pay per fish.
Honestly, I see no problem with spawning pet store fish as long as you have a goal in mind. Just wanting to get some fry or have a go at spawning really isn't a goal when the end result could very well be over a hundred adult fish needing to find homes. Also, because of the unknown element with spawning pet store fish you do have to be willing to be a little more ruthless with the culling until the consistency there.
I have noticed a lot of people never get past their first spawn. The ultimate goal for me with my wild bettas is to get a sibling pair that I can continue a line with. I never really see people on here (excluding some of the more serious breeders) going any further than a mating between the original pair. I love watching people develop their own unique line of fish as to me that is the whole aim of breeding. It's not just about breeding two fish you purchased from someone else, but rather continuing that line using your own eye and standard of quality.