The factors that I took into account when deciding upon Law were:
1 - Money anf financial security.
Having a Law degree, especially one doubled with a business-type degree such as Commerce, Economics, Finance, Business, etc; opens up alot of doors for making a comfortable living once graduated. I figure that if I am going to rack up thousands of dollars in HECS (HELP) debt, then I might as well make sure that I have a better chance of earning a higher return on my investment.
2 - Skills.
Skills and experiences that you gather from studying Law are useful in your everyday life.
It's always good to know about the Law, where you stand, and what your rights are even if you never intend on actually practicing as an actual 'Lawyer' in a courtroom.
Anyone who says bullshit about how going into Law for the money is wrong, and how they only want to 'help people' are in most cases fooling themselves.
Unless of course if you are working in Legal Aid (which I comend and applaud you 100% - It is very noble and honourable work), you will in most cases be doing the exact opposite of helping people. That, or you will eventually just get over spending every day dealing with the absolute worst side of humanity (Criminal Law, Family Law).
If you really want to do good, join Greenpeace, World Vision, or go study Medicine and work for Doctors Without Borders. Go study teaching and change the life of a child or teenager, or become a Nurse and take care of the sick and needy.
Me, I don't even know if I will even ever use my degree professionally, but I think it's a useful degree just to have in life anyway