It is really simple, just don't attempt to trick users into installing stuff they didn't want to download in the first place (anything outside the bundle they chose to download). Additional steps on install only take away from the user experience and taint the experience of the application you are wrapping.
A more apt analogy might be drug dealers subsidising medication by cutting it with heroin.
I agree. That's why I often tell people that I have higher regard for prostitution than for telemarketing - the former at least provide value in response to a genuine need (whether we feel it's beneficial for society or not). Telemarketers however, just like install bundlers, actively try to exploit people.
I'm generally under the thought that person B is always being exploited in some way or another, but there are always other cases out there.