Isn't that the logic though? The possibility of saving someone who directly/indirectly causes net gain for all of humanity? Of course the person could also directly/indirectly lead to negative gain as well.
Then you could reduce the question to be about, is risk ever worth taking.
Nine US states have "Duty to Rescue" or "Bad Samaritan" laws. If you are witness and present to a life threatening emergency you can sued, punished, and fined for taking no action... but it is said to be difficult to prosecute on these statutes.
>is risk ever worth taking
the answer is no
no risk no reward
I mean, you can apply this to any behavior. One of the obvious responses to "why should I not shoplift" is "what if you get caught?" Shoplifting is to the immediate benefit of the shoplifter and so long as they avoid the people they victimize or anyone acting on their behalf, they have no personal reason to not do it.
Care to elaborate any further?
>inb4 simple minded "no"
fuck the reward
Think more of the action and emotions that tie to the cripple than he himself. For example, a person could view him as nothing but a time and money sink, that he'd be better off dead. Another person could pity him and seek to ease his suffering. But neither thought is positive or negative. The person who believed he is better off dead might brainstorm ways to euthanize him but accidentally teach himself a new method to cultivate vaccines in a lab, while the sympathizer might seek to ease his suffering by releasing a deadly virus that kills thousands. The context of either action is neither good nor bad because it's ultimately one's view who labels them, and the inspiration in this case came from a completely neutral party.
sounds like you just hate being alive