There is a survey on Yahoo today of the 5 most disliked professions or jobs, and mechanics is one. Now this is pretty brief, and does not specify what kind of mechs, probably not aviation, but it may also apply. The problems were average salary of $36,100 and not much chance for advancement and also sometimes working in cold or dirty conditions and often with some time pressure. And you have to keep up with advancements to stay current.