That's a question we've been trying to answer.
One explanation is that the VTs were so popular in retail stores that the type is overbred. The sanctioning body, the IBC, wants to put focus on other tail types I assume. If you read the thread from the start, there are other ideas.
4 bettas: Butch, 3-year-old violet male PK EE & 3 girls in a 30 gal sorority. I do not name the girls anymore! 1/2 of them die within a month.
30 gal: 9 Oto cats, 4 Ocellifer cats. Inverts: Cherry shrimp & 2 assasin snails.
10 gal.: Butch, his 5 oto cats, 3 assasin snails, and a few snails the assassins haven't caught.