Mostly because the way we approach OOP is wrong, and so developers - who were taught to write software as "instructions given to a machine" (i.e., procedurally)

Mostly because the way we approach OOP is wrong, and so developers - who were taught to write software as "instructions given to a machine" (i.e., procedurally) - don't fully understand the paradigm. That leads to the belief that OOP is unnecessarily difficult. It's more difficult to properly decompose the problem space than it is to just add code. It really just boils down to developers being lazy and ignorant.