there is a simple explanation to this: 100% of ukrainians understand and can speak russian
100% of russians understand ukrainian but not all of them can and want to speak ukrainian
historically it has always been same country (USSR),with the Soviet Union collapse,Ukraine got its independence in 1991
since that time the country gradually adopted anti-russian stance,with things starting to get worse in 2014 when the Crimea peninsula declared independance from Ukraine(preceeded by the coup-de-etat in the country,which saw the president got overthrown and fled)
Ukraine claims Russia ocupied part of its territory,Russia claims the referendum was according to the international law.

Low ukrainian thread activity was due to the fact that none in their right mind would cut their audience by using ukrainian instead of russian language,there was simply no need for that
nowadays some of the ukrainians refuse to communicate in russian because they think Russia is their worst enemy
it has nothing to do with cryptocurrency per se,just politicing in its best (or worst)