I will be honest with you- I am super baffled on why people are continuously gambling on this shady website despite posts being scattered around in the forum alleging their genuineness. Lots of players have fell victim to their schemes where some would not be able to cash-out/redeem their winnings from the website.
The fact that players cannot withdraw money, according to 1xBit security team, is due to violating the rules.
As for the popularity of 1xBit, it is due to great marketing, smooth website operation, great design and a very large offer that meets the expectations of even the most demanding gamblers.