Greg, your use of the term "family" in its non-standard context is probably solely because we now use the term "friend" in a non-standard context. There was a time when "friendship" meant more than a sustained acquaintance with someone. Statements that friends are the ones who stay with you when times are tough (or when they have nothing to gain from you) are vestiges of this concept. It is a chosen bond that is deep, meaningful and lasting.
The problem is that artificial social constructs, beginning with 20th Century notions of politeness and ending with inane social media, have completely eroded and cheapened this word (cf. hero, courage). I can be Facebook "friends" with someone I have only interacted with perhaps once, whom I don't really care about but who wanted to add me as a friend. It's the filthy trough at the bottom of the slippery slope that the word "friend" has been on for some 100 years, the end point of its sad downward trajectory.
I will also note in passing that this entire semantic shift first became apparent when I was studying in Russia and was using the word друг, друзья for pretty much every acquaintance and the professor said, "You can't have that many friends - they're not real friends. You need to use the word знакомый instead."
The end result is that people are struggling to find words that encapsulate the classic notion of friendship, the friendship of Damon and Pythias (or something approaching it). The word "family" is one of the few ones that expresses that deep connection without losing meaning. If I said, "He's my friend" or even "He's my best friend", there's still a sense of casualness injected by the erosion of the word. If I said, "He's not a friend, he's family", then the meaning is strengthened (though in the process, the traditional notion of family is eroded).
It's yet another example of how education has failed generations of individuals who now are unable to say what they mean and mean what they say because they don't have the rudimentary skills to use their own language properly (that's not directed at you or Cannoli, but rather the great unwashed masses who are responsible for the abuse of the English language).
No, I think I can say without hyperbole that you guys are heroes for taking a stand with respect to this point. 
ἡ δὲ κἀκ τριῶν τρυπημάτων ἐργαζομένη ἐνεκάλει τῇ φύσει, δυσφορουμένη, ὅτι δὴ μὴ καὶ τοὺς τιτθοὺς αὐτῇ εὐρύτερον ἢ νῦν εἰσι τρυπώη, ὅπως καὶ ἄλλην ἐνταῦθα μίξιν ἐπιτεχνᾶσθαι δυνατὴ εἴη. – Procopius
Ummaka qinnassa nīk!
*MySmiley*
