As a mom of a child who HATES change, I know how important it is to expose him to new and different things. My motto with him was ,"Different is good." He usually responded, "different is BAD!!" That did not stop me because child who avoid change (this includes most middle schoolers) need to learn to adapt to it.
A great summer family activity would be to expose them to some "old school" games that aren't too difficult to learn. Why not try Badmitten? Ladderball is an easy game to learn. If you can find a playground with a Tetherball, let the fun begin. Croquet is another game that can be played in your yard. I bet a lot of grandparents would have some old school games hidden away somewhere. These are great games to do when you are camping and can't find an Internet connection. Let some family fun and maybe a little conversation begin!