That's not "Passive" income, if you have to attract 50-60 people per day, pretend to interview them, while subliminally encouraging them to use the vending machine. That's called a full-time job, and probably illegal, too.
And that isn't $300/day profit, he has to pay for those items in his machine. The profit is probably no more than 50%, so $150/day. For an 8 hour day, that's $18.75 an hour. That's a lot of work for not that much money. It certainly isn't "Passive."
I've been self-employed for about 30 years, which puts you rubbing elbows with other self-employed business people.
I have learned that while MOST people want to run a friendly, moral, legal business, and would never cross the line, there are a plenty of amoral businesspeople who don't have any problems crossing the line.
Furthermore, they are well-aware that many businesspeople won't cross the line, so that makes their willingness to act illegally or immorally their personal competitive edge, and they absolutely look at it that way.
They watch for decent, moral businesses, and they target them in various ways, either as a competitor, a supplier, a contractor, etc.