Talk about a complete marketing failure. No, they don't have to show transparency. Also, people don't have to buy their coin. If they're above board, they lose very little in terms of man hours in exchange for a bunch of people feeling much more comfortable buying into this. They choose to be secretive for what reason? Because transparency is annoying? How much money do they think this ICO will make with such little information given to potential purchasers.
I don't think they're going to get a very good return on their time investment here.
It's like the spelling and grammar errors in the email from a Nigerian Prince. If you are smart enough to find them, you aren't dumb enough to lose your money. The people asking those questions aren't dumb enough to give their money to these clowns, so they will ignore them because there is nothing in it for them. The people that buy their "witch hunt" accusations are their marks, so they will play it up and reel them in.