This is not about capitalists vs. working class. It's about upper middle class vs. capitalists, middle class, and working class.
When you grow up in an export-driven country, one thing you learn early is that high wages are bad for the economy. And when the economy is bad, it's the ordinary people who suffer the most.
You generally want to keep the labor share of GDP constant, which means that wages should grow about as fast as GDP per capita. If the wages grow faster than that in a field, it's probably bad for the economy. Especially if the field was already highly paid. Unusually high wages typically indicate low productivity (when measured in outputs per dollar). And when productivity is low, businesses that rely on the outputs of that field become less competitive. For example, if making software is more expensive in the US than in other developed countries, American businesses cannot afford to use it as much as their foreign competitors.