>to convince a majority of Ukrainians to revolt
Even if you accept the most charitable estimation of the number of people on Maidan in 2014, it's less than 2% of Ukrainian population. Hardly a majority.
>against their Russian dominated government
It is the government that the Ukrainian people democratically elected not a long time before the coup.
>it's a hard sell for me to believe it was not inevitable
The Ukraine was evenly split between pro-Russian South-East and pro-Western, well, West. The only chance they had for stability is respecting the democratic principles when people respect the authority of the president who won an election even if they voted for a different candidate.
The US supported the coup and broke that system. Despite famous Bush Sr.'s speech in Kiev in 1991[0] that warned of 'suicidal nationalism', the successive American administrations nurtured Ukrainian nationalism, supported and fed it.
>its existence as a buffer state controlled by Russia
Ukraine being neutral was enough for Russia, but not for the West.
[0] https://www.youtube.com/watch?v=Vkjxf76xRTw