Qtum is confirmed scam, you can watch this in Qtum Ann theard.
What is the reason for being a scam. I think the ICO is not over yet and they are conducting a huge promotional campaign too and it is a sad thing to see more scams and what is the conclusion now as no one from Qtum has responded to it and they have not deleted any messages too in a self moderated topic.
I did checked the ANN thread of Qtum and still monitoring them to confirm to myself if they are an actual and confirmed scam.
But seeing it's thread, it's looks like it's just an accusation and still they are backed up with big guys behind this project.
And I don't think this project is an actual scam.