The thing is, all of the information that can be obtained from a whois search, can also be obtained freely elsewhere.
It's not a matter of someone doing a whois to find out your info, a whois is used to determine who owns the domain, period. Like I said, the information contained in a whois is information that is typically publicly available elsewhere anyway.
Now in regards to them doing it just to make money.....indeed. However, what's wrong with that? That's what business is about...making money. Just as you are in business to make money, and find ways to make more, they do to. That's a healthy business in fact. You recognize a need, then you fullfill it.
Keep in mind that there are quite a few free hosting providers. Does that mean you're a bad person or business for charging for hosting?