I hate to say it, but I'm a tradesman, have not been to uni, and I think it's a fairly good bet, that (last year not withstanding) I probably earn more than anybody else on this board.
You CAN find good places to work in, they are about. Sometimes you have to travel to get what you want. At the moment I'm living in Brisbane, and commuting to Melbourne, Hobart and Launceston to work. I know some mechanics who do make good money, but they're also very good operators.
Half the problem is that people don't like the money of apprenticeships. Possibly because apprentices seem to be older when they start now than in the past. $15K would be fine if you were 15 or 16 and still living at home. But If you're 18, have a car and want to have a life, you can make more at McDonalds flipping burgers. It all depends on what you want. If you want a trade, you put up with the crap money to get your papers. But once you have them, nobody can take them away, and you have something to fall back on. If you leave the trade after two or three years, what have you done except waste two or three years? You could go to uni, but I seem to remember they don't pay you to go there either.
Bits of paper make the world go around.
Nothing comes for free.