This casino gets over a million visits per month. In your opinion, are these few complaints a lot, compared to the number of customers?
You think a million visits per month is a lot? LOL!
Roobet.com, for example, has 3x more, Stake.com has 7x more, and Freebitco.in even has 60x more than that.

source:
https://www.similarweb.com/website/roobet.com/#overview
https://www.similarweb.com/website/stake.com/#overview
https://www.similarweb.com/website/freebitco.in/#overviewMoreover, there is no direct correlation between the number of visitors and the number of customers on the site. Only 10% of 1xbit.com's total traffic is direct traffic, while almost 30% is referral traffic. Compare that to other gambling sites, and you'll see the difference.
Has 1xbit ever published any information about the number of users on their platform? No? I wonder why.