The most common used wagering requirement for withdrawal without any bonus is 1x-2x, 5x is a bit rare but I know some casinos with such requirement.
About the casino mentioned above, I have never tried it as it seems to be less popular casino.
Better to stay in most reputable casinos with standard 1x-2x wagering requirement for withdrawal.
I agree with you and I know that maximum gambling sites allow their user to withdraw their fund after 2x wagering. And also I was not aware about this type of requirement that they have to use 5x requirement of the first deposit requirement. I think it is too much. As I had not received/accepted any bonus offer why I have to make such wager like 5x!!