That's not true, the wagering requirement doesn't decrease the chance of money laundering but it increases the chance of users losing their deposit and it benefits to casino. Imagine that I am a gambling addict, deposited 1 Bitcoin, lost 0.2 Bitcoin and now I want to withdraw because I'm afraid to not lose more but then there is a wagering requirement that forces me to continue gambling in order to withdraw and that's definitely increasing my gambling addiction issues.
Wagering requirement on deposit without deposit is part of money laundering prevention, agree or not but it is the most used reason why there is wagering requirement on deposit.
Logically it reduces the chance of money laundering because people who knows about this rule will think twice if they want to use the casino as mixing service or to launder their money.
Coming to your example, if you are afraid to lose more then why did you deposit more than what you can afford to lose? In this case, you are the one who make the mistake.
I only support the wagering requirement when there are bonuses because a bonus is free money and it's fair to make free money hardly acquirable but when it comes to the money that I earned and deposited, I shouldn't be forced to wager 2 times or 5 times.
To be fair, I don't understand why Trustdice requires 5x wagering for first-time depositors, that doesn't make sense to me.
I'm trying to be neutral here although I also do not like the 5x wagering requirement, but in fact it is written in their ToS which means that once you created an account then you made a deposit = you are agreeing with the terms.
So no one is forced to follow or to agree with the terms, once we notice there is a term that we dont like, simply ignore and leave the casino then find other casinos.
All in all, any casino reserve the right to have terms as what they wish and we as players also free to decide whether to agree with it or not.