At first I assumed it was because of liquidity problems and not because they wanted to screw customers. But in the hearings later he refused to answer a bunch of easy questions. E.g. the following meme is literally what he said: https://www.reddit.com/r/wallstreetbets/comments/lngem6/do_y...

Q: "Do you realize that you literally manipulated the market. Yes or No?"

Vlad: "Thank you for the great question. When I was a boy in Bulgaria [ladida]"

If he had been honest in his dealings then he wouldn't have had to evade every question posed to him.