I am not necessarily campaigning for the Sox to pick up Harvey, but the above reason certainly shouldn't be a determining factor. This group may be tight-nit, but they also aren't very good at baseball. Harvey in his final year of control doesn't do much for me (if he was controlled beyond this year, it may be worth the minimal risk), but not taking a chance to improve the club because everyone likes eachother is no bueno.
This year was never about competing, but I expected to at least be a halfways decent team (low to mid 70s wins). Some of these guys are going to need to learn to win at the major league level at some point. It looking like that won't be happening until 2019.