Well yes, it's discretionary. That's what discretionary means - you can use it for whatever you want. Using it for savings or investment in no way invalidates my argument, because that's exactly what I'm talking about. If you have a bunch of money in savings, then getting hit with a $215 fine isn't a big deal, you can pull that small amount of money out and pay it. But the whole point is that since the extra "revenue" you get from a higher salary is discretionary, then you should be able to easily absorb a small fine, but a company with large revenues doesn't necessarily have a lot of discretionary cash.
Now it's certainly possible that your investments aren't liquid enough for you to free up the $215 to pay the fine, but that's a different situation (and is your own damn fault). Companies can be in this situation too, but don't mistake the existence of this situation as a refutation of my argument, because it's not. My argument at its core is that a person making $100k can be expected to much more easily be able to absorb a particular fine than a person (with the same cost of living) making $50k, but you can't necessarily say this about companies, because a person's salary isn't dependent upon how much they spend, but a company's revenue is, and so if company A has a higher revenue than company B that does not mean company A's profits are higher.
Now it's certainly possible that your investments aren't liquid enough for you to free up the $215 to pay the fine, but that's a different situation (and is your own damn fault). Companies can be in this situation too, but don't mistake the existence of this situation as a refutation of my argument, because it's not. My argument at its core is that a person making $100k can be expected to much more easily be able to absorb a particular fine than a person (with the same cost of living) making $50k, but you can't necessarily say this about companies, because a person's salary isn't dependent upon how much they spend, but a company's revenue is, and so if company A has a higher revenue than company B that does not mean company A's profits are higher.