This is the pragmatic view to take as a user. However, I don't think it's how we want sites to operate. Facebook's ToS state:
For content that is covered by intellectual property rights, like photos and videos (IP content), you specifically give us the following permission, subject to your privacy and application settings: you grant us a non-exclusive, transferable, sub-licensable, royalty-free, worldwide license to use any IP content that you post on or in connection with Facebook (IP License). This IP License ends when you delete your IP content or your account unless your content has been shared with others, and they have not deleted it.
I think this violates the grant that the user is giving Facebook. If they deleted the content, it's supposed to be gone - Facebook no longer has a license to display it on their site. Facebook has, in public communications, stated that the qualification there is about their messages where you could send effectively an email to another person and both sides have to delete the message - just like with email.
As human beings, we should do a lot of things for pragmatic purposes. That doesn't make it good. In a certain way, it's like knowing that you live in a neighborhood with a criminal and "well, I guess it's my fault that I didn't lock my door or even bothered to go out of the house."
I'm all for Facebook changing to try and do new things, but sometimes there's a lack of consent that's disturbing given that Facebook has been telling users to expect control over their sharing. We've seen articles about the ability for third parties to add you to a group and for that adding to be advertized to your friends. I understand that we should consider anything we post to Facebook public. However, Facebook has strongly encouraged us to put things we don't want public on Facebook with an assurance of privacy. As such, I don't think it's unreasonable to rake Facebook over the coals over this (if it's true). It's the type of bad behavior that should be admonished.
I'm certainly not arguing that companies need to do what their users want or anything like that. However, we call out bad companies as bad. In this case, it looks like they're even violating their own ToS (if the story is true). If Facebook had started out like Tumblr or Twitter or Geocities where you're really trying to post public content, it would be one thing. Facebook didn't start out that way and, in fact, encouraged us to think of them as protecting private content. Let's say Google decided to sell or publicly display your email tomorrow. We'd admonish that. It's a violation without your permission. Is the reason we should consider things posted to Facebook as public that we've seen Facebook be scummy for years now and should have learned that their promises are nonsense?
I don't think you're wrong or anything. I just think that "buyer beware" or "well, you shouldn't have rented an apartment in that neighborhood" are great ways to look at it.
* P.S. Nothing in this comment is meant to cast judgement on whether or not Facebook is doing the things the article accuses them of. I haven't researched it. It's simply to note that Facebook portrays itself as both 1. not sharing your content further than you allow and 2. allowing you to remove content other than things like messages which might be in someone else's inbox. If they're violating that, they're violating what they're telling users.