That is the problem of some sites who are offering a lil bit lower house edge than others. They couldn't maintain the operations or let's say, they can't cope up with the competition. Even though they are offering lower house edge, yet, the sustenance is quite hard especially if you have no sufficient bankroll on hand. So I would say, sometimes it is better to play with known sites even if they are offering like 1%, but you know for sure when it comes to payout, you will have no problem at all.
Actually safedice has been establised for more than 2 years before it turned to like this. At that time, they was running smoothly without any problem from player and there was an user who won more than 100 btc on there (afaik they successfully cashed out). So with that fact i doubt if the reason why they aren't active anymore because of low house edge they offered.
Lower house edge is much more better than having no edge at all where you cant able to pull up funds either on users win or maintenance of the site.
100 BTC win would surely wreck em up if their entire bankroll isnt really that too big but they should at least put up some max winning on a small percentage if they
do really like for their business to last longer because if they would continue it out then it wont really be a sustainable one.