I've had a number of jobs where I've had to go through a codebase and optimize code written by these people.
Somewhat extreme example: at previous company it took in excess of 6 hours to open certain project files (probably more), but we were able to reduce it down to < 5mins
Not specifically these two people, but more generally the people who just do whatever without any thought about performance, algorithm design, data structure selection, etc. As the codebase grows the problems get progressively worse, so better to do some SWE with every addition