I find such people irritating but partially right. Some forms of work may be hard, physically taxing, and often unpleasant because of it, but compared to sedentary jobs are healthy and might rightly give you a sense of achievement. Some might result in health problems because of the physical demands, but there are problems such as obesity related to jobs where you're sat at a desk all day, eye strain as well if it's with a computer in front of you. A good example is olive pickers in Greece compared to those with office jobs - one might have a more comfortable, much more well-paid job but I know whose body I'd rather have. You need more than physical reward and pride in your work though, and manual labour isn't paid for in full. Of course that's largely to do with immigrants working for much less, but it's certainly true that that side of the work sucks and to argue otherwise you must just like the cheap labour.