I'm not saying your FC should hate each other. My FC is a subset of my LS. All FC members belong to the LS, as well as others that are not in the FC. We get along fine. However, we're competing with 3-4 member FCs that won't merge and pull some of our best members away because they're real-life friends. These members still expect to run with us, but it undermines the functionality of the FC.
If you want the social aspect, use a LS. For content, use FCs. If you want both closely tied together, do what I described above.
Adapting means playing the shout party and Duty Finder game. I'm doing it, and it's ruining the game for me. Meanwhile, one functional static in our FC is shooting ahead and leaving the rest of us behind. Progress comes down to luck, not skill like it does in organized teams.
As I said, it undermines the purpose of a FC and puts many people at a disadvantage for endgame content. What are we going to do when there's 24-man content? Shout parties? If you think it's hard getting 8 reliable people for 8-man content, just imagine 24-man. No thanks.