There are a couple of them out there.
During the 11 months I experienced very poor connection stability, I was quick to complain that some engineers didn't get to the root cause(s) of the (various) problems.
However, I was equally quick to praise (officially) those who did tick each problem off as fixed.
It wasn't always the engineer's fault that he was the wrong type of engineer - sent by his employer to deal with the wrong type of fault, despite Plusnet specifically requesting SFI engineers on some occasions.
So, I would say there are far more than "a couple" of them out there