Well it's the bitcoin fever, that's it and they are mounting this wave.
Still the site is nice designed, it's a waste to think they decided to use it for a full large scam rather trying to run it as a legit one.
Maybe they made the min withdrawl so high because they made a bet on the outcome of the revenue from the site. If they are able to cash in so many money from ads/popups to cover the cashouts and make a profit too, they will honour them for a long term stable investment, otherwise they will simply run with what they made and let the site slowly die.