That's a really convenient narrative based on the fallacy of homogenizing Ukraine. Let's take a look at a few slides from this lecture that Mearsheimer gave back in 2015 to get a bit of background on the subject. Mearsheimer is certainly not pro Russian in any sense, and a proponent of US global hegemony. First, here's the demographic breakdown of Ukraine:

here's how the election in 2004 went:

this is the 2010 election:

As we can clearly see from the voting patterns in both elections, the country is divided exactly across the current line of conflict. Furthermore, a survey conducted in 2015 further shows that there is a sharp division between people of eastern and western Ukraine on which economic bloc they would rather belong to:

Maybe learn a bit about the subject first.