Have you considered the following two possibilities. First, they may not be legally allowed to tell you much. Second, if they reveal all the things that flags their system then it becomes easy to bypass it?
You tell that to the people who have lost life-savings, life-changing amounts to these scam exchanges. You tell that to the clueless customers who forever wondered what happened to their hard-earned money. They got no proper explanation, no response even.
The possibilities you're talking about are the most convenient ways for these scammers to steal money. Forget about legalities. I'm sure these behaviors and alibis can't stand in a court of law. If only it's easy to bring these scumbags to court.
Yes, I will gladly tell them because they are the ones at fault. Deal with it,
stop running away from responsibility. Read the terms of service before you send your money away to something. If you believe that you have been wronged, then go ahead and sue. I wonder why practically no allegedly scammed party tries to sue.

Everything is the user's fault, nobody was forcing them to do this. If you don't understand the risks of your actions, you are entirely to blame. Nobody else but you.