Not the OP, but I think part of the answer is that society benefits from ensuring a certain amount of baseline rights, privileges, and opportunities are open to

Not the OP, but I think part of the answer is that society benefits from ensuring a certain amount of baseline rights, privileges, and opportunities are open to all its citizens, even when it's inconvenient. It's not just a moral position, it also helps ensure one group doesn't consolidate power and resources. For example, I would want to make sure you still have access to voting even if it costs a disproportionately high amount of money to ensure that right for you or if it's much more probable that you would vote against my personal selfish interest. We generally want a society with a shared set of core principles rather than just a purely transactional society.