Pro Bono lawyer living out of his car

I have this feeling that i'm going to be a Pro Bono lawyer living out of my car. My professor raised an interesting question the other day. Why does the market determine who can sue and who can't? For example. In house lawyers have to make work for themselves so if they want to motion for this or that they can and will because it is in their best interests to do so. Another thing is it is questionable for who the courts are open for. Imagine yourself an immigrant worker whose boss obligates them to work long hours sometimes compiling 160 hours in a two week span and that boss only pays them a flat rate instead of mandatory overtime (its happened to me to). Imagine that because you are an illegal alien you are affraid to bring suit due to the fact that you could be deported. I know there are recourses but how many of them are real? So I could picture myself running free law clinics to the under privilaged because I see such a need for them.