The ones I see doing it never have had any pride in the job,or work ethic, and have done it since day one of employment because they think the company is always screwing them.Snark, I think the average driver would agree that clock milking is an outdated concept. And it drives a lot of honest folks crazy that it still happens. Not as common as in the bad old days, but there are still people who milk the clock for all its worth and get away with it.
I wouldn't report a clock milker. But if I saw it enough times I might be motivated to say something to the driver in question, if only to find out why.