because the job sucks. You get to inhale toxic fumes, ruin your eyes, get splatter burn on your skin and work in all sorts of rough and dangerous conditions and die young. yes it takes great skill to be a fabricator/welder and if your good it pays well but the down side of the job are considerable. It's a similar deal with driving truck. Lots of job, pays well but the job sucks. Living life on the road, taking t he occasional shower, the crappy food. Beats being unemployed but not job most people want.
This is where I differ from many. If I needed a job, and even if the job "sucked," I would take it even if temporarily. I have caught chickens, hauled hay, cleaned out chicken houses, umpired ballgames, done general farm/ranch work and whatever else I needed to do to survive around here until I got the job I currently have. While I get to work in a nice environment now, if I lost my job today, I'd go back and do those other jobs in a heartbeat if it meant being employed and making a living.
I think people get too locked in to what they will/won't do to earn a living. My older brother lost his job and was unemployed for 4 years because he was too proud to take a job driving a truck or working in the oil field. If he couldn't get an office job, he wasn't going to take it. That caused a hardship on our family, especially my dad, for a couple of years. I don't know how many people have this problem (at least I see it as a problem) but suspect he isn't the only one.
Also, to the point, I also suspect (but have no proof) that some won't take some jobs because they are unwilling to relocate. Again, as much as I love where I live (sorry Mott ) if it meant me making a living, I'd relocate in a heartbeat, at least, hopefully, temporarily.
To sum up, there are lots of factors that contribute to one's being unemployed, and sometimes, though certainly not always, I feel that it is their own fault.