breeding pet store bettas isn't so much universally bad as it is unpredictable. you might come out with beautiful offspring, or you might end up with a hundred or so unsellable, or worse, disfigured babies that you now have to either care for yourself, or cull nearly an entire spawn.
So remember, when you're feeling very small and insecure,
How amazingly unlikely is your birth,
And pray that there's intelligent life somewhere up in space,
'Cause there's bugger-all down here on Earth.
Loki/Grendel/Gail/Beowulf/Camilla/River/Bathory/Arwen/Lafayette/Deb/Jack Skellington (soon)