Because real martial arts (even though WTF TKD is complete ass and only ITF is good) in a game based around them isn't good anymore. We all want fire kewl mlg litning scr0lz.
I feel that scrolls based off of actual martial arts could be appreciated still if they have functionality, alot of people are grabbing some of the flashy new scrolls because they have a gimmick.
You can go around with slash but if you want a new variants why not make one based on tekken characters as all you have to do is just record or cut a command list together.
Here's a site where ppl get most of their sprites. You need to click on a character u are looking for, and then scroll all the way down for the sprites. Some of them lack sprites, so it's recommended to mix them up. http://www.fightersgeneration.com/characters.html