I can’t get into the heads of it’s creators, I don’t know what they were thinking. However they created a thing that is absolutely abysmal at being “state independent currency”, addresses the wrong problems incorrectly, to the detriment of what needs to be addressed. It’s sluggish, expensive, volatile, inconvenient, and offer zero error-protection or any protection really. For criminal usage those cons are outweigh by the fact that it’s anonymous and is outside of the laws. For running scams you couldn’t create better environment. You can also gamble on it’s volatility. For anything else it’s less then useless.
Whether or not it was created with crimes in mind or not is not even that relevant.