I just checked and it shows they have 500+ online which is actually pretty huge because stake as a huge casino and sportsbook has on average 1800 online which means there is not a huge discrepancy given they have sportsbook too.
The feedback was already over 3 years, the fact that they are still operating until now, that means they have survive and for sure they can clean their name since there's no scam accusation or any negative feedback I have read against DuckDice.io anymore.
We can read the opinion of the people, but regardless they can still run their business even with negative feedback.
Although the red tag against them is quite disturbing but if they improve and give a good service by now to their users then I think those things can be ignore.
And Yahoo is right on his thread created since it's really good to review the tags for quite sometime since for sure those things has been improved by a site if they are still running by now and I guess it's worth to try to play by now but it's still on the players decision if they can risk or just pass this one.