1> Why should the boat (infrastructure) be in the Ocean (attached to the Internet)? As previously stated, "profit" is not an answer.
A ship should be in the ocean to bring bananas to North America, and generally get things to people eho need them. Foreign governments should not fire missiles at those ships. The internet made up of infrastructure , and can itself be considered to be critical infrastructure. It makes no sense to ask why it should be connected to itself. I see now you must have read the phrase "critical infrastructure " a lot and forgot that the word "critical" is there for a reason. Kind if like "fighter jet" - most jets aren't fighters, and most infrastructure isn't critical, so if you mean to distinguish critical infrastructure from Sony's PlayStation infrastructure please do so. The stock exchange should be network- connected so you can save fir retirement without paying a broker $150 transaction fee every month. Public health systems should be connected for fast, effective response to a public health crisis.
> Someone breaks into your house and rapes everyone inside, then steals everything of value you have no recourse
If that happens, you should be imprisoned. You failed to protect your family from armed attack. If you disagree , there's your answer to #2. We hold people accountable for what they DO. We don't hold people accountable and imprison them for getting raped or otherwise attacked. We imprison (or kill) the rapist, not the victim.
The attacker is at fault, not the victim. (The victim may have been foolish in the case of some crimes, but no amount of street smarts will protect you against a hostile super power on the rise.) You cannot protect yourself against China. They have zero-days, they have moles, and no company has the resources to fight China single-handedly. In this, I know of what I speak.