Right. Take their annual report, divide the net income by the number of employees. Call that 'X'.

Then do the same for some big tech companies. Call that 'Y'. The employee count is way less than for Exxon.

Most likely, Y >> X. Vastly greater.

So to a corporate bean counter, the "value" of an Exxon employee, X, is about what they're paying them now. Hiring one more, even a brilliant tech guy, will have a negligible effect on any numbers they care about. Especially since he'll be frustrated by the dinosaur culture and his inability to have any impact.

You can say "you're wrong, what about <new energy thing>?" Well, this finance guy understands Exxon's numbers pretty well.