Save it for econ class. A company's goal is to build a sustainable profit generating engine. To allow this, it needs to play a constructive part in the marketplace and community.
A company does not need to provide a constructive part of the community to achieve their goal of profitability... they just have to provide something that some segment of the population is willing to pay for, or build in a degree of lock-in that guarantees continued profits.
For example, It's probably fair to say that Monsanto is not a constructive part of the marketplace and community, but they sure do have a sustainable profit generating engine.
Edit - if you're going to downvote, how about some discussion as to how this comment does not add to the conversation... since I'm sure there was some other reason for the downvote other than not agreeing with me :)
And if they're not a constructive part of the community, the community has every right (I think it's practically an obligation) to berate them for it.
Just having a business plan and making money should not protect you from criticism or absolve behavior detrimental to the general community! Yes, legally Craigslist has no obligations; that's why nobody's litigating. I argue that morally (at least from a utilitarian standpoint), Craigslist does have an obligation to play nice. And so I welcome critical blog posts and bad publicity.
Oh, I agree 100% that if the community disagrees with the behavior of an entity they they have every right to berate them. And if a company behaves poorly enough, it will open the floodgates for competitors and revenue loss (i.e. GoDaddy during SOPA probably lost an appreciable number of customers).
That being said, in this specific case I think that whether or not there is a moral obligation to let a third party scrape and mix-in your data is very debatable (given that Craigslist does not provide an API).
Sure, people should play nice. And some may interpret playing nice as 'don't scrape other people's stuff for your own startup'. Or at least don't be suprised when they get pissed ;)
You could take tabaco companies, much of alcohol, gambling, TV and other addictive "entertainments", and to the extend that they are enterprises (if not legal), much of the arms trade, mafia / organized crime, illegal drugs trade, and modern banking, as not providing net social benefits. While generating profits.
Lets get to basics, If product was providing value and doesn't anymore there will be attrition to userbase and that is the gist of it. It is also the foundation of wealth building and whatnot. Ancillary benefits, as APIs are, help shallow out the curve of obsolescence or even grow the product sometimes if cards are played right, but that is that...
