There is a culture that the l33ter the code, the more senior I am. So, many people will never refactor code to make it simpler to read. It affects their ego. In fact, I've seen the opposite: simple code refactored into more complex (not by the original author). The mindset: if it's more complex, it must be better.

Java example: rewriting non-stream collections code to use lots of chained streams. Using lambda functions when not needed. Rewriting case labels to use case lambdas. etc.