Does this means it will be bad if it's used by the bad people/criminal to pay their bail?
Token holders decide which bail they want to pay via their preferences. So it's not the "person" arrested paying their bail. It's their friends and family requesting a bail payment on their behalf. Then the payment request is matched with token holders who are willing to make micropayments to help someone get out of jail.
You have to remember the person arrested hasn't been charged, so they are considered innocent. Yet, they are held in jail awaiting trial and in the meantime, they lose their job, can't pay their bills, can't take care of their family, etc. This could be someone arrested for driving with a suspended license because they forgot to notify the driver's license office of their new address.
Take a look at this video to see how it works for token holders: https://youtu.be/iY-DbpXXW1w