I've got to disagree with you on part of this, but I think it comes down to the two different things you're talking about here. One is having a family unit with a partner, etc.; and the other is having a home base, and a support system. You may be right about the former. I'm not sure that I see JJ settling down with one guy or girl, but then again, that may be just what he needs. On the other hand, I think JJ needs his family a lot more than he's willing to admit. I'm not saying that it's a near-obsession (like it is for JP and Will), or that tradition dominates his attitudes (like it does with Darius), but it's still pretty important. Look at how he reacted when the house in Boston wasn't on schedule to be completed. He acknowledges that as his anchor. I think he looks at his family with a jaded and cynical eye, but if you dig deeper, he needs them. A lot.
A very good point. It makes sense that failed relationships would warp his thinking about that. On the other hand, it's hard to say what the future will bring. If Darius or Will (and maybe even John or Marie) end up with largely happy, monogamous relationships, that will surely have an impact on his attitudes. As he gets older, and matures, that will also guide him more in that direction. That's not to say that he'll go there, just that he'll feel some internal pressure to do so.