The tradition of celebrating the Christmas was weeded out by Soviets. In 1917 Church was officially removed from participating in governing the country and from power also. Soviet Union was a secular state and though religion practice was not, strictly speaking, forbidden it could cost you a career if you were spotted in the Church.
Since then the rich Russian tradition of celebrating the Christmas came to the end. After 1991 when SU had ended its existence these traditions became slowly reintroduced, though, I think it will never be celebrated in such a way it used to be before the revolution. Though, I must admit, that Russian Orthodox Church is making great efforts of re-introducing the practice. Orthodox Christmas (celebrated on 7-th of January) was declared an official holiday regardless of the fact that over 30% of the Russian poopulation are Muslims and some another great part is the Jews.
(That hardly seems fair since Islamic and Jewish New Years should also be declared holidays then Of course that means that I won't go working these days).
For Russia Christmas is a religious date, not just the day when you don't go to work, so it's celebrated mostly by those who feel religious and whom that date seems important to.