Some competitor could be not happy with it
Extortion demands are pretty irrelevant, I was in communication with one such person before and I asked him if he really expects anyone to pay and his response was along the lines of: "lol no, but it's fun to make people stress over it"
Short of a public confession, the source of DDoS's are pretty much unknowable. However, I've had nothing but positive interactions with other site operators, so I don't subscribe too much to the hostile-competitor theories. Most of us are in the same boat trying to make bitcoin gambling strictly superior to fiat gambling.
Regardless of the origin, the course of action is always the same: hardening the systems against further attacks. So let's just assume the best, and not sow too many seeds of distrust =)
Wise words as always , this is why I like you most among the other shitty dev , and Dooglus too I like his attitude as well as how he take care of scam site Dadice lol. Oh well at least there is no ddos anymore