There communist movement has a global and international component which the nationalist and Western conservatives do not have.
They have 87 parties in that country, how many of them are fronts for the communists?
To be fair, in Ukraine the politicians are mostly
controlled by the oligarchs, and both in turn mostly answer to outside actors: The Pro-West side to (if one wants to pin it down to one location) Brussels, the pro-Russian pols to Moscow. IMO the Nationalists would go their own way if they could, but with an ongoing combination invasion / civil war on their hands, they have no choice but to lean hard to the West.
Insofar as the ouster of the Commies goes, it has to be kept in context: The situation is grim. This invasion / civil war is heavy duty stuff, and the opposition is NOT a bunch of ragged groups with AK-47’s. They have heavy weaponry including very capable anti-aircraft systems and tanks, and a great many opposition fighters have military training, with many straight out of Russian military or intelligence. I would say that the so-called “Nazis” are being considerably more tolerant of the Communists than Abraham Lincoln would be, if in the same situation.