"Exxon has had continual focus on efficiency and reductions through attrition"
Not true. Exxon doesn't primarily reduce workforce through attrition. They reduce workforce mostly through forced rankings and continuous culling of the bottom tier. They have been doing this for decades which has led to a terrible company reputation among employees (go checkout their layoff board for reference). But even with this toxic policy, DW has a higher approval rating than MW. BTW MW just adopted this terrible policy for CVX going forward. What a surprise.
The layoffs obviously hurt MW's approval ratings with employees, but its not the primary reason. He's a chaotic leader with terrible results even by his own board's metric. If the company had a clear vision and the results showed it was working then his approval rating would reflect that.