we are not talking GUARANTEES here. But half the people who have JDs are not working in the legal profession. 7 years of higher education, and including all the hoops you have to jump through to get a license, and then so many either cannot find law jobs or cannot keep them that they have to go into some other field? That is a very high risk gamble. You have to bet 3 years of your life, 3 years of hard work (most of which has little to do with actual practice (but I guess you would not know that, not being a lawyer)), and then the hoops, and then 6 figure debt or near it, all for a 50 percent chance of success?
RISKY GAMBLE! Law school is not self improvement, but instead a high risk gamble, a gamble that eats up 3 years of your life. Why not just go to vegas and get it over with quickly?