Actually, it does, and Adam Smith pointed this out over 200 years ago (he also noted the collusion that was typical among employers to suppress the wages of labor), noting the expense, trust, and risk assumed by would-be lawyers in determining their pay:
Education in the ingenious arts, and in the liberal professions, is still more tedious and expensive. The pecuniary recompence, therefore, of painters and sculptors, of lawyers and physicians, ought to be much more liberal; and it is so accordingly.... We trust our health to the physician, our fortune, and sometimes our life and reputation, to the lawyer and attorney.... Fifthly, the wages of labour in different employments vary according to the probability or improbability of success in them. The probability that any particular person shall ever be qualified for the employments to which he is educated, is very different in different occupations. In the greatest part of mechanic trades success is almost certain; but very uncertain in the liberal professions. Put your son apprentice to a shoemaker, there is little doubt of his learning to make a pair of shoes; but send him to study the law, it as at least twenty to one if he ever makes such proficiency as will enable him to live by the business.
http://www.gutenberg.org/files/3300/3300-h/3300-h.htm#link2H...