To that end, of course, the "speed run" strategy for building a business involves roping a whole lot of people into various tenuous obligations, delivering enough on your promises that the whole thing doesn't collapse, and then terminating contact with people as they cease to further your life plans [0].
The survival truth is that if you were going to behave socially like most mammals do, you'd remain shy and hesitant before trying to interact with a stranger - you'd keep physical distance, take a gentle posture, run away if startled, and only gradually get closer. And in a group, you wouldn't try to push other members around too casually, lest they catch on and get you exiled.
But what we keep telling ourselves is to encourage trade with everyone from the first instant, which is ripe for aggressive strategies like the ones depicted in the article, and also more opaquely predatory ones like panhandling, cons, blackmail, or protection rackets. It's so ingrained that we can barely see how toxic and abusive an environment it creates.
You can do business the slow way. It takes a lot longer, you miss a lot more opportunities, and it diminishes your probability of being part of the global elite from "slim" to "none", but you'll also rest easier at night, and you're less likely to be taken in by someone who will use your good nature against you.
[0] http://kernelmag.dailydot.com/comment/column/9497/why-i-rank...
Edit: And I should add that sometimes you can find a good, solid reason to step up and socialize - just, you need to plan it in advance with the understanding that you're going to be making win-wins.
I sincerely do not want or expect any favors or benefits from them. If we're in a setting that begets conversation and I know that we don't have tooo much in common, I'm going to go out of my way to make the conversation enjoyable for them, because their enjoyment of the conversation will make the conversation enjoyable for me as well.
The alternative is often either side taking turns about subjects that the other person has no interest in, and those conversations don't do any good for either person.
Don't kid yourself into thinking they wouldn't do the same for you -- instead, think of it as a mutual agreement to provide services to each other when needed.
E.g. to ask you if you want a particular contract (when it needs to be fulfilled regardless). Not to 'come up' with a contract because your 'bro' is out of work.
Examples of what I took to be humour:
"It is a mistake to lecture people on your own pet subjects, as this columnist has discovered."
"Brown-nosing ahead"
Are not the connections built in this way fragile?